BIQUARTERLYMAGAZINE OFTHE SOCIETY FORGENERAL MICROBIOLOGY VOLUME 26MAY 1999

Physicsunder the microscope Taxonomyfor the new millennium Howmolecules cross membranes Let'shave a debate! F

SGMHeadquarters MarlborouqhHouse Articles BasinqstolieRoad SpenciersWood Physicsunderthe microscope Dave Roberts 50 ReadinoRG7 1AE It'sallaquestion of image Tet.0flB9BB 1800 Fax 01189885656 Dave Roberts &Gianfranco Novarino 51 e-mailmtoday@ Atomicforce microscopyA lastair socgenmicrobiol.org.uk Smith 54 SGMWebSite Cryo-electronmicroscopy: taking backthe knight http:,/www.socgenmicrobiol.org.uk Stephen Fuller 56 Editor DrDave McL. Roberts Crystal log raphy and the atomic anatomyof viruses DavidL Stuart, Jonathan M. Grimes,Nick Burroughs & Editorial Board DrUlrich Desselberqer Peter P.C.Mertens 59 rrolessoruave Kowtanos Nuclearmagnetic resonance (N M R):keeping pace with ManagingEditor microbiologySte phen Matth ews 62 JanetHurst Produetion Editor Whata Ramanspectrum can tell the microbials6nlnnicl lanAtherton NozomiYtow 64 Assistant Editor and Bacterialclassification and taxonomv: a'orimer' forthe new BookReviewManager millenniumHowardGest JaniceMeekings 70 Gontributions Meetin g preview:Del iveri n g the goodsB ruce Ward 74 Theseare always welcome and shouldb'e addressed to the Editor Let's have a d ebatel Philip Mortimer 77 (c/o SGM Headquarters). GopyDates Lastdates for receipt of copy atMarlborouoh House are: Regular Features LieneralUODV no lnternationalDevelopment Fund reports IZ Augustissue 10 May Novemberissue 1 3 September SocietyNews AOVefttSemen$ (vKU) Above: Partofthe This issue ol M icrob i ol ogy FebruaryCouncil Meeting 80 Auoustissue 7 June structureofthe core of Todaylocuseson biophysics Notices 80 NoVemberissue 1 1 October bluetonguevirus. andthe applicationsthat are NewsofMembers 80 Advertisements relevantto microbiology.lt Photocou rtesy J. Diprose, Staff News BO Allenouiriesshould be senttor includesin-deoth articles on InaCocks,NWH Sales Ltd, J.Grimes,D. Stuaftand Grants 8l Ramanspectroscopy, Cryo- CedarHouse, Cedar Lane, R.Esnouf JohnRedwood MPvisits Marlborough House 82 EM,imaging, NMR,X-ray Frimley,Surrey G U 16 sHY PrizeLectures and Awaros 83 Tel. 01276 685 1 1 I crystallographyand atomic Fax 01276 6850 1i TOrcemrcroscopy, Meetings 84 SpecialMailings Molecularmethods are Allenouiriesshould be sentto: Hotoffthe Press 86 (SGM revolutionizingmicrobial JaniceMeekings Gradline RO Headquarters) classification,but on p.70 Tel.01 18988 1802 HowardGest questions the GoingPublic 90 Fax0l l89885656 validityofsomeof the resultant e-mailj.meekings@ , Reviews 92 socgenmicrobiol.org.uk changesto taxonomy. AddressBook Subscriptions 1999 TheSGM meetingat 95 NON-MEMBERS Edinburghwas a great SGM Staff 96 Mi cro b i o I ogy Tod ay 940.OO success.The nextmeeting at (us$70.00) Leedsin September promises Diary 103 MEN/BERS to be of equalmerit. The range Comment 104 Allmembers receive M icrobiology of interestingsymposia are Today. ln addilionth ey may take anyofthe Society's journals. outlinedon p.84 anda preview of theMain Symposium'How OrdinarvMember Membeiship Subscription (inc. Do Molecules Cross Microbial Other ltems Mi c r o b i o I o gy To d ay) 937.00 Membranes?aoDears on Review:SGMSymposium Volume 57 (us$65,00) p,74. Also relating to Society DieterHaas 66 Micro biotogy960.00 (US$ 1 1 0.00) meetings,Philip Mortimer JGyS60.00(us$110.00) raises Feedback 94 /JSBC50.00(US$80.00) the subjectof debates as a meansof scientific Studentor RetiredMember (p,77), MembershipSubscription (inc. communication Mi cro b i o I o gy Tod ay) 920.0O Severalimooriant events to (us$30.00) fosterthepublic understanding Mi cro b i o I ogy S,32.00 (U S$60.00) JGyS32.00(US$60.00) of science,such as SETweek, take placein the spring,SG M Theviews exoressed bv contributorsare not necessarilv isan activeoarticioant and thoseofthe Societv: nor can the our recentactivities are claimsof advertiseisbe describedon o,90. guaranreeo, Thesealcicles aooear in O 1999 The Society for General additionto alltheregular Microbiology ISSN:1464-0570 featuresand reportsof Societyactivities. Des i g n : Grap h i cs Inte rn ati o n al

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It's all a question of image DaveRoberts &Gianfranco Novarino

History the depth of field and parts A picture is wortb a tbousanduords, as the saying goes. The of the specimen which are ability to visualize microbial structures and processesis a out of focus will clutter up I central part of the communication and, in many cases,the and technically degrade the I understanding of our discipline. image.In realapplications it I Your eyesare forming an image of the letters on this page is necessary to tfade the I I becauseyou are able to resolvethe adjacent parts ofeach gteater depth of field of i letter into its black and white components and so discern lower numerical apeftures its shape. If you were to move the page away from you, with the lossof resolutionto I I the letters would form smaller and smaller images on your get the bestcombination. I retina until you were no longer able to resolve the black and white parts and only seethe text as a grey blur. The angular Contrast separation of any two points on the page which can be The capacity to resolve an i separatedby your eye is a measure of resolving power and object is ofno use unlessyou is called the acuity. Its absolute limit is when the two points can seeit; that is, it has to fall on adjacent retinal cells. be different from its back- i To seesmaller objects, we can use lensesto form images ground. Many microscope which appear to be larger and thus are resolvable. test objects ate high- I I Magnifying glassesare an example of this principle, well contrast, typically being completely opaque,which helps ABOVE: known for centuries. If it has been known for so long it is to separatethe different components of lens performance. Twospecies ofthe peniculine crliate I FrontonialF,vernalis (green) and I reasonableto ask whether today's microscopesare really A number of ways to enhance the level of contrast have leucaslfuonthesediment ofEsthwaite I I better than thosefrom the turn ofthe century or arethey just beendeveloped. WaterThe black background indicates easier to use? Is there any new physics in the modern thatthe microscope wasset up for I dark-fieldillumination. Eachcell is instrument? Stains, Perhaps the most obvious way to increasecontrast about200 pm long COURTESYBTANO EI\LAY INSTITUTF OI i is to apply a stain. Surely every microbiologist must have FRESHWAIFRECOLOGY t I Lensdesign and aberrations done a Gram stain, the first stageof which, staining with r I The theory of microscope lensesand how to get the best crystal violet, demonstratesa clearincrease in the contrast of BELOW: from them was essentially worked out by Ernest Abbe the objects. Bactetta that were once translucent become Thesessile pertitrich Vorticella sinilis l photographedunder DIC Note the working in the University ofJena, Germany. The formation an opaque purple and stand out clearly against their illusionofoblique illumination caused I of an image by a lens dependson the diffraction of light. background. The inverse ofthis process,negative staining bythe brightening ofthe left side and thedarkening School-levelphysics tells us how lenseswork, but there area with, for example, nigrosin hasthe samegeneral effect. ofthe right edge The I roundobject in the lower portion of number of imperfections in the image formed which arean Completion of the Gram stain illustrates a second thecell is the contractile vacuole. I inevitable consequenceof the processof diffraction. For principle of staining, which is the capacity ro use chemical Bar100 pm COURTESYNICOTA IV]ILLER SGl!1 I example,the diffraction of light dependson its wavelength, reactionsto discriminate morphologically similar objects. t so that an image formed with white light has a slightly This is one areain which considerableprogress continues to I different place for each component colour, resulting in be made. I images having a coloured fringe around the edge, and generally reducing the sharpnessof the perceived image. Dark field. \7hen light interacts with a specimen it may This is called chromatic aberration. There are a total of six do so in severalways. It may be occluded by an opaque basic kinds of aberration which are corrected by careful specimen, resulting in a silhouette, absorbedat one or more design of the component parts of the objective lens, all of wavelengths, resulting in a coloured image, or the light which waswell understood by the end of the l pth century. may be re-directed or scattered. Light scattering by small particles is known asthe Tyndall effecrand is the mechanism I Resolution by which we seedust motes in a sunbeam.The objects being I t Traditional microscopy was, and in purist circles still is, seenby this method are often too small to be resolvable judged by the simple measureof resolution. Resolution is a directly. Dark-field microscopy works by arnnging for the t questionofhow closetogether two objects can be placed and objective lens to collect scatteredlight so that the specimen beperceived as two objects.It is almost entirely governed by is seenas a bright object against a dark background. In the angleformed bythe light from the edgesof the objects as technical terms this improves the signal-to-noise ratio and it entersyour eyeand, therefore,the wider the cone of light, gives a particularly powerful technique for detecting low- the better the resolution. The light-gathering potential of abundanceobjects. the microscope objective is measured by its numerical apertureand the greater the numerical aperture, the higher Phase contrast. Many microbes are essentiallyhyaline but the resolution. The downside of this relationship is that the that does not mean they have no effect on the light which higher the numerical aperture, the shallower the depth of passesthrough them, which may be changed in phase or field will be. Real specimensare almost always thicker than polarity, although neither change is visible to the eye. In

ffitrfiffiffi#ffi6#e#ffiyroDAyvol26/MAy99r UPPERROW: practice polarized light (a) Theciliate Nassula aurea. ln mlcroscopes are most brightfleldKrjhler illumination and (b)with DIC These images show that commonly found in a thetwo systers show di{ferent aspects mineralogical context and ofthe cell and that D lC is not always are uncommon in biology, theautomatic choice ofilluminat on systemBars,100 pm but Frits Zernike was IOURIESYNICOLA[,1 LtER SG[,1 awarded the 1953 Nobel Physics Prize for the phase- LOWERROW: (a)An unldentifled species ofthe contrast microscope which stichotrichcilLate genus 0xytricha allowed changesin phaseto photographedunderDIC The blue be made visible. Essentially backgroundcolour isan artlfact ofthe DICconfiguration Thecirri clearly this is done by making the visibiearound theedge ofthe cell are light passing through an compoundciliaand because oftheir sizeare best seen under DlC, object interfere with light (b)The stichotrichcil aleStylonychla passing through the back- phase nytlIus phologr aphed under ground. This interference may be additive, causing a However, Iike phase contrast, the halo generated by a contrast,Notethe loss of detail particularlyatthe anterior (top) end of brightening, or subtractive, causing a darkening in the strongly fluorescent object can obscure more weakly thecell due to swamping bythe haio image. The cell may be alive and moving and otherwise fluorescing objects nearby.Many fluorochromes also bleach Bars100 pm unstained. This technique is probably best used in when they areexposed to UV light and sofluoresce for only a COURTISYNICOLA[,1LtER SGI\I microbiology to observefine projections, such aseukaryotic very short time. The use of scanning high intensity light BEL0WT flagellawhich are exceedingly difficult to observein life by sources,typically lasers,can help to overcomethis problem. Theciliate D idi ni u n nasutu n labelled any other technique. The disadvantage ofphase contrast is withanti s tubulintagged with fluoresceinandphoiographed under the halo which it createsaround an object which can be so Depthof field UVlight The tubulin in the cytoske eton bright asto obscuredetail. The problem of depth of field is facedby those who want to thelabel andin the cilia has taken observecomplete systemsrather than thin sections. The revealingthetwo girdles ofcilla and thelongitudinaL organzation ofthe Interference contrast. Strictly, all microscopesform their parts of the specimen which areout of focus exist asa diffuse cytoskeletaLfibrilsThe cell is 140 pm images through interference, but in the interference blur which detracts from the clarity of the in-focus image. long the optics are artanged so that the COURTESYSUE|]OPE NAIURAT HISTORY [IUSEUX/ contrast microscope interference is most sensitive to the rate of change of the Holography.In principle it is possibleto take a holographic optical properties, hence the system is known asdifferential image ofa drop of water which could then be re-createdby a interferencecontrast or DIC. The optical principle of this projector and studied using a conventional microscope. To method was first describedin the late 1lth century byJamin our knowledge, there is no published record of this ever but it was the work ofNomarski in the 1950s that made the having been done. The formation of the holographic plate is technique easilyavailable to,the biological laboratory. a processofconvolution which cannot readily be reversedby DIC images are difficult to interpret becausethe effect of computer becauseof the complexity and, particularly, the the interference is as though the specimen was obliquely sizeof the calculations necessary. illuminated creating a pseudo J-D appeannce.The contrast effects are, however, demonstrating differences in the Confocal microscopy. The new-kid-on-the-block optical path properties, not the actual thickness. Real cells the confocalmicroscope, which once again has its roots in do not often look like fried the 19th century.The true microscope,i.e. an instrument eggs with a protruding capable of forming a real-time image, was patented by nucleus. Minsky in I95l andmechanical instruments were produced a decadelater. In the late 1970s the advent of comparatively Fluorescence.UV light was low-cost digital computers and lasersmade the instruments first used as a microscope more widely available and by the early 1990s it was a illumination sourcein 1904 practical proposition to havethem in biological laboratories. by Kcihler, in an effort to The principle of the confocal microscope is to use an improve spatial resolution. optical stop, a small hole, at the objective'sprimary focus. Instead, the far more use- The effect of this is to allow only in-focus light rays to pass ful property of specrmen through. To turn this pin-point into an image it has to be fluorescencewas discovered. scannedover the specimen. This takes real time, of course, Like dark-field illumin- and renders the system of limited value to moving (live) ation, the fact that most specimens. The removal of out-of-focus information from materials do not fluoresce the resulting image results in what is known asan optical gready improves the ability section and repeated sections can be built up within a to study those that do. computer into an effective solid model.

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The loss of total light by the very small confocal aperture affordable video cameras in the 1980s brought a new ABOVE: path hasto be compensatedfor either by useof a photomultiplier technique to microscopy.The first video cameraswere based Swimmingof the chrysomonad f lagel late S p u m e I la eI on g ata illustr ated or by an enormousincrease in the intensity of illumination. on tube technology and were prone to a number ofproblems I usingdigital film A conventional video Sfith very intense illumination it is necessaryto be able in terms of accuracyand resolution. These days tubes are clipwas recorded using DIC 0ptics a I CCDcamera and a ,o discriminate the illumination (background) from usedonly in specializedcircumstances. U-[/laticSP VIR. The I clipwas converted intodigital format .he interferencepattern that is the image. This is done most The charge-coupleddevice (CCD) | is a semi-conductor usingaRadius digital film card on a effectively by employing fluorescence to shift the wave- array which accumulates charge when a photo lands on one [/Iacintoshc0mputer, Single frames I (duration1/25 s) were extracted from length of the light to be observed and to filter out the unit. These chargesare read off at a standard I time and the thedigital clips and assembled into illumination source,exactly as in a standard fluorescence system is re-set for the next image. The I data are run together asingle still-image file, microscope. If the illumination source is suitably con- into a standardTV signal in most cameraswhich is passedto Ihenumbers onthe left give the time J inseconds/frames Bar,5pm ..ntrated, normally a focused laser,then only the region of a recorder I video or a computer digitizer. In the latter case, COURTESYGNOVARINO, NAiURAtHISTORY tnstantaneousinterest is illuminated which considerably the digitizer board has to try and dismantle ]\4USEUII,l I the signal back r"ducesthe impact ofphoto-bleaching. into the cell I units of which it was first composed. One I problem with CCD camerasis I that the array accumulates I Deconvolution. The combination of in-focus and out-of- random signal as a result of thermal noise. This can be lr.. focus information is called convolution and is well defined considerably reduced, and the I sensitivity of the camera mathematically. It is possible to achieve the confocal effect consequentially increased,by cooling the chip. I *ith a normal microscope by reversing the process,which The tumbling price fast I of personal compurers and large .un be done ifyou have | a sufficiently powerful computer and storagedevices has now opened the field ofdigital video asa I you know a great deal about the optics of the instrumenr. routine application in the laboratory to record and study fne latter issueis the real srumbling block. In practice, dynamic processesunder the microscope.There have, It asyet, I however, microscope images can be grearly improved by been comparatively few published studies in microbiology a.convolution. I exploiting the potential of this technique. I I Timeand the movies I lmageanalysis There is more on the collective mind of modern biologists Once you have I adigital image, then many forms of image ,han mere I description: the recognition of the dynamic processing are now possible and these techniques are a of biological processesand interactions demands powerful addition to the microscopist's arsenal. Apart from I "uture systems capable of producing images of changing deconvolution and I work on 3-D images, there has been very tpecimens. The halo effect in phase contrasr, for instance, little progressin image analysismethods I since the early I ratherlimits irs usefulnessin the caseof actively swimming 1980s. These techniques are,however, rather mathematical I nugellates,when DIC is a more appropriate choice. If the and tend to be driven from the command line of a computer. ..lls slow down then phasecontrast again I once becomesthe Few things seemto put biologists offmore effectively, so pro- I method ofchoice. gressin computer-assisted microscopy has largely come with Furtherreading I' I improvements in software design making it easierto use. The Royal Microscopical I Cameras Society (RMS) handbook series The original microscopeswere intended to permit visual Developments is recommended, particularly I the titles listed below. I observations.Film cameraswere added later ro allow the It should, we hope, be clear from the above that very little Bradbury, S. & Bracegirdle, imagesto be recorded,although anyone experiencedwirh a new physics has entered the field of microscopy since I B. (1998). lntroduction to Li ght microscopewill know that the information I captured on film the development of phase contrast. Nonetheless, today's M icrampy. MicroscopyHandbook I is often only a fraction of that availabledown the eye-pieces. instruments will, in most but not all circumstances,out- Series, )4 pp. Oxford: BIOS The first constrainr is the amounr of light. Film perform their turn-of-the-century Scientific Publishers, in I equivalents. association with the RMS. .-ulsions trade the amount of light neededto exposethem It is in the field of technology, of new combinations I Bradbury, S. &Evennett, P. the grain size,i.e. the resolution, ofthe photographic of known physics, chemistry and mathematics that | "Sainst (l 996). C ontra st Techn i ques i n i-age. Advancesin the chemistry of emulsion production microscopy is I developing now. Since we srarted with a Light Microscopy.Miroscopy and processing,especially of colour emulsions, have greatly clich6, we should end with I onetoo-!0u ain't seennffin' yet! Handbook Series, 1 18 pp. Oxford: t.lieved this limitation. BIOS ScientificPublishers, in I Nonetheless,for motile cells the associationwith the RMS. I length of time needed for exposure inevitably leads to O Dr Dave Robertsl and DrGianfranco Novarino2 call, c. (L996). Views of I motion-blur. The use of a flash tube is still the best way to work in the Department of Zoology at the Natural J. the C ell. A P ictorial H istory. overcomethis problem, to deliver a high-intensity burst of History I Museum,Cromwell Road, London SW7 58D American Society for Cell light of very short duration. Sadly few modern microscopes (FaxO1719388754) Biology. I 1 I- are,or canbe, equipped with flash tubes. Tel.01 7 1 9388790; e-mail [email protected] Sheppard, C. & Shotton, D. I 2Tel.01 7 1 93891 03;e-mail [email protected] G997 ). C onfocalLasa Scanning I - Video M icrwnpy. Micros copyH andbook Series, 106 pp. Oxford: BIOS The amount of available light has been a limiting factor in I Scientifi c Publishers, in I the use of cine film in microscopy, but the arrival of associationwith the RMS. I -r

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E Atom ic force m ictoscopy AlastairSmith

The principleof the atomicforce microscope therefore there is the potential for observing biological Microscopeshave historically beentools ofgreat importance processesin real time. Severalinstruments arecommercially in biological science.The atomic force microscope(AFM) availablefor around f 100K and in general the technology is is one of a famlIy of scanning probe microscopeswhich straightforward to useand occupiesonly a small table top. has grown steadily since the invention of the scanning tunnelling microscope by O Highresolution imaging Binnig and Rohrer in the There have been many studies of biological materials using early eighties for which AFM in the few yearssince its conception, including nucleic they received the Nobel acidsand their complexeswith proteins, two-dimensional Pilze for Physics in 1986. protein crystals and individual isolated proteins, mem- The AFM usesa cantilever, branesand membrane-bound proteins, and living cells. usuallymade from silicon or One of the most extensively studied systemsis nucleic silicon nitride, with a very acids which have now been imaged with sufficient low spring constant, on resolution to measurethe pitch of the double helix. Nucleic the end of which a sharp acids may be deposited on mica quite simply by using a tip is fabricared using divalent cation to bridge between the negative backbone of semi-conductor processing the nucleic acid and the negatively charged mica surface. \When reports of AFM ABOVE: techniques (Fig. 1). the tip is brought close to a Most recently there have been several Fig. t. Electronmicrograph ofa typical sample surfacethe forces between the tip and sample cause imaging of the complexes formed between proteins tappingmode AFIVI cantilever shown and this motion can be detected and DNA which have, for example, provided detailed upsidedown to reveal the sharP tiP the cantilever to bend usedfor imaging Bar 100 pm optically by the deflection of a laserbeam which is reflected information about the changesin conformation of DNA in COURIESYDIGITAL 1NSIRUI\,1 ENTS,VIECO cantilever.Ifthe tip is scannedover the responseto protein binding. The one-dimensional diffusion IlIETROTOGYGROUP offthe back ofthe sample surfacethen the deflection of the cantilever can be of RNA polymerase along DNA has been imaged in real TOPRIGHT: recorded asan image, which in its simplest form represents time and the enzyme was seento slide along DNA and even Fig.l. [tlagneticAF[,4image ofa the three-dimensional shapeof the sample surface.Many hop to neighbouring nucleic acids on the substrate surface. garnetfilm showing flower-like AFM imaging of a magneticdomains, variants now exist which use special tips to probe the Fig. 4 shows one recent example of COURTESYDIGITALNSTRII/ENTS, VEECO electric, magnetic (Figs 2 and 3) or thermal properties of protein/DNA complex. Tapping mode AFM has been used IIFTROTOGYGROUPAND V FRATETLO surfaces,and even optical spectroscopyis now possible with to image an individual complex of human transcription BELOW: about 50 nm lateral resolution using scanned probe factor 2 with DNA. It appears that a protein-protein ofa ilig.ft. Magnetic AF[4 image techniques. interaction has facilitated looping of the DNA to allow two praseodymium-iron-boronpermanent distal DNA sites to be brought together on the substrate.A magnet, The resolution of AFM dependsmainly on the sharpness COURTISYDG TAL INSTRUI\nENTS. VEECO of the tip which can currently be manufactured with an end goal of someworkers is to develop AFM imaging techniques [IETROLOGYGROUP.AND R.STRITT radius of a few nanometres. Atomic resolution is easily to a point where the DNA sequencecan be read; however, obtained on relatively rolust and periodic samples.Soft this ambitious goal remains elusive. sampleshowever, particularly biological samples,provide a The highest resolution images are obtained on tightly more difficult surfaceto image becausethe forcesexerted by packed structures such as two-dimensional arrays of the tip during imaging can causedeformation of the sample' proteins becausethe packing affords a greater mechanical The problems involved with imaging soft samples have stability to withstand the imaging forces.In casessuch as been overcome to a large extent by the introduction of this the resolution of the images is better than 1 nm because tapping mode AFM imaging. Instead of maintaining a the highly regular assembly of proteins also allows constant tip-sample distance of a nanometre or so, the averaging to be performed which greatly improves the cantilever is oscillatedin a direction normal to the sample signal-to-noise ratio. The quality of information in such resulting in only intermittent contact with the surface.This images has been demonstrated by Engel and co-workers greatly reducesthe lateral forcesbeing applied in the plane who have reported real-time observation of the central pore of the sample which are responsiblefor most of the damage of proteins in the HPI layer of Deinococcusradiodurans asthe tip is scanned.The AFM is capableof better than 1 nm opening and closing. Another example,shown in Fig. 5, is lateralresolution on ideal samplesand of 0'01 nm resolution the molecular resolution tapping mode AFM image of the in height measurement. periplasmic surface of OmpF porin from Escbericbiacoli There are some significant advantagesof AFM as an taken in buffered solution. A rectangular unit cell arrange- imaging tool in biology when compared with compli- ment(a = I35 A, b = 82 A) c^n be seeneach containing two mentary techniques such as electron microscopy. Not only porin trimers with a lateral resolution of about B A. doesAFM achievemolecular resolution but the technique Imaging of living cells is not straightforward becausethe requires almost no sample preparation and, most cell surfaceis extremely soft despite the structural support of importantly, can be performed under fluids, permitting the cytoskeleton. Obviously deformation of the sample samplesto be imaged in near native conditions. The fluid during imaging can seriouslylimit the resolution which can may be exchanged or modified during imaging and be achievedon cells and although the overall shapecan be

ffi &ffiffi sffi effih#ffiYroDAYVOL26/MAY99 measuredeasily, surfacedetail is difficult to obtain. In some molecules has been observed by several groups and casesthe nucleus can be cleaily seenin the images, which measured to be of the order of a few hundred piconewtons. suggests that it is less easily deformed than the cell mem- The resolution of the AFM asa force or binding strength brane, and movement of the actin filament bundles beneath measuring device is of the order of about 10 piconewtons, the periphery of the cell membrane hasbeen observed. limited by the thermal noise of the cantilever at room temperatufe. An exquisite example of the measurement of Measu rement of biolog icaI i nteraction forces such biomolecular interactions was reporred by Lee and co- In addition to the porential of the AFM to provide very high workers at the Naval Research Labs in \Washington. Two resolution images of biological samples and to monitor complimentary DNA oligonucleotides, one tethered to the conformational changes and biomolecular processesin real tip and one to a gold substrate,were allowed to interact and time under native conditions, rhe instrument is alsocapable then pulled apart whilst the forces required to rupture the of manipulating molecules and measuring the strength of double helix conformation were measured. biomolecular interactions with piconewton sensirivity. Perhaps one of the most exciting demonstrations of the The forces exerted between the silicon nitride tip and the potential of the AFM to measurebiomolecular interactions sample arise principally \Waal's from van der interactions. has been the recent demonstration by Gaub's group, and These interactions arc rathet non-specific in the biological others, of the mechanical unfolding ofsingle proteins. Gaub sensebut lead to bending of the cantilever which provides hasshown that the forcesrequired to unfold the subdomains the topographical information for the images. However, it of titin, the giant muscle protein, can be measuredby AFM. is relatively straightforward to modify the tip surface In theseexperiments the AFM tip is used to pick up part of chemically so rhat its interaction with the sample may be the vast titin molecule whilst the rest remains absorbedto a made highly specific. For example the tip may be modified gold substrate. The tip is then withdrawn and a seriesof to havea charged surface, one which readily forms hydrogen small tugs on the cantilever can be observed which have bonds or may be made very hydrophobic. In thesesimple been attributed to the unfolding of the immunoglobulin ABOVE; casesit is the interaction with the sample which bends the and fibronectin domains. The forcesmeasured are in two Fig"$. lmage ofthe periplasmic surfaceof0mpF porin fron [. coli, cantilever and therefore the information that is contained phases.First, the extension ofunfolded chains which appear COURTTSYDIGITAIINSTRUI\,lENTS. VEECO in the images has chemical information about the tip- to fit well to a worm-like chain model and second, a I/ETROLOGYGROUP,AND A, ENGEL sample interaction. Tip dramatic step which is identified with the catastrophic . modification is usually unfolding of a domain. This type of measurement, which achieved using the well has initiated a flurry of activity in mechanically manipu- known processof thiol self- lating biomolecules, is only the first step in a developing assemblyon gold. The rip is new field ofbiophysics basedonAFM technology. first coated with a thin layer ofgold by evaporation, then Thefuture immersed in a solution of The fact that AFM is relatively cheap technology and rrr-functionalized alkyl thioi straightforward to use suggests that it will be accepted molecules. These molecules quickly as animagingtool in biology. The ability to perform LEFT: have a functional head group real-time observationsof biological processesunder natiye Fig.,5.Tapping mode AFM image which will provide the tip conditions will be ofgreat inrerest and asthe biochemistry is ofan individual complex ofhuman transcriptmnfactor 2with DNA with the desired physico- developed to modify tips in more complex ways to attach COURTESYDIGITAT JNSTRUIIIE|\]TS, VTECO chemical properry and an proteins, peptides and small organic molecules, then the MEIROTOGYCROUP, AND C, BUSTAI\IAN]E alkyl chain spacer of about 10 carbonsterminated with a detailed measurement of biomolecular interactions appears thiol group. The sulphur sponraneouslyforms a covalent to be an areawith very great potential. The simplicity of bond with the gold coating on the tip and the molecules the instrument also lends itself to integration with other pack tightly to form a well ordered monolayer with the instruments. In the author's laboratory, as in severalothers, functional group uppermost, creating a new surface of AFM is being combined with laser spectroscopyso that tailor-madechemistry on the tip. mechanically induced conformational changescan be moni- Tips may also be modified to have biological function- tored by fluorescenceor infra-red specrroscopy.It seemsthat ality. For example, antibodies can be tethered to the tip AFM is likely to become one of the most widely used high via flexible polyethylene glycol spacers,permitting the resolution microscopy techniquesin the biological sciences. antibody to bind to an antigen on a sample surface.Using such a tip, the distribution of antigens over a cell or other O Dr Alastair Smith is a lecturer in the Department surfacemay be mapped, but it is also possible to pull the of Physics and Astronomy atthe lJniversity of Leeds. Furtherreading antibody-antigen complex apart by moving the tip away His current research is focusing on the application of Bookmark the following from web sites: the substrate on which the antigen is absorbed laser spectroscopy and scanning probe microscopy and measure http://www.di.com the strength of the interaction directly. The to the study of biomolecular structure and dynamics. http ://www.thermomicro.com binding event between single pairs of streptavidin/biotin e- m ai I d.a. m.s m ith @leed s.ac. u k http://www.molec.com

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Whycryo-EM? Vitrified samples An instructor in an introduction to an X-ray crystall- The preparation of a sample for cryo-EM takes advantageof \When ography course some years ago explained the difference the properties of water. water is cooled slowly (a few between electron microscopy and X-ray diffraction as degreesper second)it forms hexagonalcrystals of ice, the structural techniques. Imagine, he said, setting out to form found in ice cubesand snow flakes. Very rapid cooling determine the structure of a man. One approachwould be to (thousands of degrees per second) traps the water in a coverhim in a suit of armour, place him in a vacuum until all vitrified state in which the structure has not been allowed to the water is gone and broil him under a high energy beam rcarrangeinto a crystalline form. Practically, this is usually until the armour began to melt and flatten, and finally take accomplished by a method developed 20 yearc ago by a picture of the remnants and call it the structure. That, he Jacques Dubochet and collaborators at the European said, is the electron microscopist's approach. The X-ray Molecular Biology Laboratory (EMBL). A small aliquot crystallographer, in contrast, maintains his sample in an of the sample in suspensionis placed on a holey carbon aqueous environment and determines the stfucture of the film blotted to generate alayer of - 1000 A thickness and entire sample in three dimensions rather than only that of a plunged into a bath ofethane slush held in a container of shell of a metal shadow or a heavy metal stain. From such a liquid nitrogen. Ethane is a very efficient cryogen since. BELOW: perspective, the choice between the two techniques was an unlike nitrogen, it doesnot boil at the temperaturesused Fig.1" Cryo-electron micrographs of obvious one to any seriousstudent ofstructure. for vitrification. Nitrogen is not used directly since the SFVtaken on a PhilipsC[/200 equipped the situation has changed dramatically and few formation of gas around the specimen when it is introduced withafield emission gunat 2 !m Today (upper)ard 4 pm(lower) underfocus, structural biologists would omit electron microscopy as into liquid nitrogen slows the cooling and leads to the virionssit in a layer The700 A diameter part of their characterization of a biological system. The formation of ice. ofvitrified water suspended overthe is not an equilibrium one but rather a holesofa carbon film The phase advent of cryo-electron microscopy (cryo-EM) has allowed The vitrified state contrastnature ofthe image causes the observation of biological samples in a layer of vitrified metastable one. It can be maintained at liquid nitrogen differentresolution ranges tobe water. This avoids the drying associatedwith classical temperatures for long periods. Our group has examined accentuatedatdifferent defocuses, COURTESYSTFPI]ENFULLER approaches.The useofphase contrast to image the specimen specimensstored in liquid nitrogen for more than 10 years allows one to perform un- without loss of the vitrified state. Raising the temperature stained microscopy so that above about -140"C causes devitrification and the the entire density of the formation of cubic ice. Paradoxically,vitrified water freezes specimen contributes to the upon warming. Cooling the sample again does not restore image. Image processing the vitrified state, it simply generates cooler ice. The techniques have developed vitrified sample is transferred to the microscope by passing so that the contrast ofthese it rapidly between baths of liquid nitrogen and then images can be accentuated mounting it in a liquid-nitrogen-cooled specimen holder and the three-dimensional which is inserted into the microscope. Other schemes structure determined by have been used for generating vitrified specimens. The combining the projected requirements are sufficiently rapid cooling to avoid the densities iri the individual formation of ice and maintenance of the vitrified state by micrographs. Finally, mea- keeping it at low temperature at all times, usually by storage suresof the reliability of the in liquid nitrogen. resultant structures have The requirement for very rapid cooling is a limitation been developed and vali- of the technique. The method works best with specimens, dated by comparing them such as suspensionsof viruses or protein complexes, which with structures derived can be made very thin so that cooling is rapid. Thicker from X-ray diffraction of the objects such as cells must be handled differently and same complexes. This has represent a challenge to the field. Suspensionsamples also led to the use of a divide present problems if they contain solutes which interfere and conquer approach to with vitrification. Samplescontaining salt or sucroseshow a many systems. First, the phasepartitioning after vitrification. Crystalline specimens atomic resolution stfuctures are usually handled in a somewhat different way. These of subcomponents of a samplesare often placed on a continuous carbon film in macromolecular complex glucoseor tannic acid and cooled directly in liquid nitrogen are determined by either or in the holder rather than using ethaneas a cryogen. This is X-ray crystallography or possible becausevery high concentrations ofthese sugars NMR. Then, cryo-EM is used to provide a context for act asa cryoprotectant and inhibit ice formation. these structures by showing their placement in the The vitrified sample is typically maintained at near complex and indicating where the structure must be -170'C during microscopy. The specimen is extremely altered during assembly. sensitive to radiation damage from the electron beam of

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differencesbetween separateparticle images reflects the LEFTI changein orientation rather than samplevariation. iiil. I Three-dimensional reconstructionofSFV generated from Three-dimensional reconsrrucrions of particles with 10000 particle images such as th0se higher symmetry, such as icosahedralviruses, are parti- seenin Fig 1 Thetriangular profiles of thespikes are seerl as well as the thin cularly well developed.Building on algorithms formulated proteinsheets which overlie the by R.A. Crowther (MRC Laboratory of Molecular Biology, membraneofthe virus. Cambridge), a number of groups have developed methods COURTESYSIEPHENFIJTLER for treating the caseof icosahedralparticles. More than 150 such structures have aheadybeen published and the number continues to grow. The useof a highly symmetric particle allows the symmetry ro serveas a guide in determining the orientation and makes the process of computing the structure itself much more efficienr. Tesrsfor symmetry in the particle images allows identification of thoseparticles in the microscope. An image of an undamaged specimen is the population which have been distorted and hence would obtained by using low dosetechniques. The specimenis first blur the reconstruction if they were included in the average. imaged at low magnification so that areasof interest can be Reconstruction methods have also been developed for non- identifiedwith minimal irradiation (< 0.1 elecrronsA 2;. symmetric particles particularly by the groups of M. van The image is then captured at higher magnification with Heel (London) and J. Frank (Albany, USA). The power of the first electrons to hit the specimen. Typically, the image these methods has recently been demonstrated by high is formed with a dose of 5-10 electro.rt A-2. \Work with resolution reconstructionsof the ribosome. crystalline specimensat -17 0 oC indicates that this dose doesnot damage the structure at resolutions coafserthan Cryo-EMcomes of age 104. Cryo-EM and three-dimensional reconsrruction are The images obtained by cryo-EM show details of the undergoing a renaissance.A few years ago, the best entire specimen.In contrast to negative staining or metal icosahedralreconstructions achievedresolutions of slightly shadowing which show the surfaceof the sample, as the better than 304. Higher resolution was the domain of armour models the featuresof the knight, the image is a electron crystallographersand others working with ordered superimposition of all of the density in the sample. Inter- specimenssuch ashelices. Two developmenrshave been key preting such a projected image requires either restricting in bringing a new exciremenr to the field. The first is the oneselfto the edges of the object or accounting for the establishment of methods for processing large numbers projected nature of the image. Three-dimensional of images and combining them to produce a three- reconstruction techniques take advantage ofthe fact that. dimensional structure. Combining thousandsof particles the image is a projection. The most powerful approach is enhancesthe relatively low signal to noise ratio in the that of electroncrystallography. However this can only bd unstained,low doseimage of a single particle. The second applied when the specimen is co-operativeenough or the development is instrumental. The useof high voltage and investigator inventive enough to produce the sample in an field emission gun sourceshas increasedthe strength of the ordered two-dimensional crystal. The simplest of the high resolution information transferred from the specimen alternativeapproaches takes advantageof the homogeneity to the film. This is a consequenceof the fact that the image of of the specimen. A field of particles such as the one of a thin unstained specimenis dominated by phasecontrast. A Semliki Forestvirus (SFV) shown in Fig. 1 can be viewed more coherent electron source produces a better phase either asimages of separateparticles or asimages of the same image. The effect is particularly important for images of structure from a variety oforientations. The latter is key to single particles. Accurate determination of orientations determining the structure. The process of three- requires refinement against high resolution information dimensional reconstruction involves identifying the which is, in turn, necessaryfor enhancing the signal to noise orientationsofeach ofthe views representedby the particle ratio at hi gh resolution. imagesand then combining these images to determine The determination of rhe fold of the hepatitis B capsid the structure (Fig. 2). Obviously, the reliability of the protein by the groups of R.A. Crowther (MRC, Cambridge) assignment of the orientation and the resolution of and A. Steven (NIH, Bethesda,USA) from the icosahedral the information contained in the image limit the final reconstruction of hepatitis B coressignalled a coming of resolutionof the structure. A pfocessof refinement allows age in the field. The methods used by the two groups one to determine the orientations to higher reliability; exemplified the two developments described above. The howeverthis processis only effective if the resolution of the Cambridge group used thousands of images raken on a data allows determination of the orientations with high microscope equipped with a field emission gun sourceto precision.The homogeneity of the sample is critical to this producea7'6 Aresolution reconstrucrionwhich allowed process.The reconstruction method assumes that the visualization of the cr-helicesof the structure. Srncethis

$f$$#ffi#ffi $#r#ffiy ToDAyvoL 26lMAy99 E marvellous demonstration of the potential of the methods, a of independent hemispherical sectorswith closely packed, number of groups have applied this approach successfully ndially arranged Gag protein under the membrane with to larger systems. $7ork by W. Chiu's group (Baylor, defects in the packing between the sectors.Second, the Houston, USA) on herpesvirus and our group on SFV (Fig. particles do not all have the same structure and hence 2) haveproduced structures at better than 10 A resolution in averaging of images cannot make use of this basic property. which secondarystructure can be identified. This progressis Approaching such a system requires a continual interaction not limited to icosahedrally symmetric structures. The between biochemists and structural biologists to prepare work on the ribosome mentioned above has now reached homogeneous subassembliessuch as the helical tubes resolutions of B Aand is serving to map out the changesin formed by segments of the Gag protein. It also will require conformation with the functional stateof the system. methodological developments such as the improvement of The increasedresolution and demonstrable reliability of techniques for cryo-EM tomography to determine the the information provided by the combination of cryo-EM unique structures of individual particles. and image reconstruction have altered the gentle rivalry The future of the technique remains full of promise. which once existed between X-ray crystallographersand Although methods are still under development, current electron microscopists into a respectful working relation- techniques have reachedsuch a level ofsophistication that ship. Three-dimensional structures derived from cryo-EM they can be applied in investigating a very broad range of not only provide context for the higher resolution structures biological problems. No longer arewe restricted to working of components but are also increasingly used to investigate on the best behaved systems.Cryo-EM has passedfrom large macromolecular complexes by crystallography. The being a tool ofthe specialist to being an essentialtool ofthe determination of the structure of the bluetongue virus core microbiologist. by D. Stuart's group (Oxford) (seep. 59) utilized a three- dimensional reconstruction from B. Prasad (Baylor, O Dr Stephen Fuller isa SeniorScientist in the Houston, USA) to generate the initial model used for Structural Biology Programme at EM BL, Postfach phasing. The progress on the crystallography of the 10.2209, Meyerhofstrasse7, 691 17 Heidelberg, - ribosome has been aided by the use of reconstructions to G erm any (e-m ai | : stephen.f u I I er @em bl h eidelbe rg.d e). serve as an initial phasing model and a control for heavy Hisgroup focuseson the use of cryo-EM and atom phasing at higher resolution. three-d i men si o nal i mage reco n structi o n for the study of enveloped viruses,membrane fusion and the Thefuture: promisesand challenges microtubule cytoskeleton as well as cell biological Cryo-EM alsoprovides resolution in time. The vitrification techniques for the study of ER-Golgi transport. method can be adapted to capture intermediates. The approachdepends both on the timescaleand the system but alarge range of conditions is accessible.\We employed a simple spray technique in which the blotted grid was exposedto a mist of low pH while it was plunging towards the ethane bath to examine the structures formed by the SFV spike during the first 50 ms after exposureto low pH. At this early stage, the virion remains icosahedrally symmetric and hence a three-dimensional reconstruction could be performed by standard methods. Simple mixing experiments have allowed us to examine the slower interaction of the pH-activated virion with the target vesicle. Naturally, the structure does not remain symmetrical upon contact and hence other approaches must be used to determine three-dimensional structure. Despite the recent progress,challenges still remain. A typical example is shown in the image of immature HIV (Fig. 3). HIV is an ideal casefor'divide and conquer' since the structures of parts of all the structural proteins are RIG HT: fig.$" Cryo-electron micrographs now known. This image contains a wealth of information. ofimmature HIV produced by infected It shows the layer of spikes on the surface, features cellsin the presence ofprotease within the membrane itself and the radial arrangement of inhibitors.Theenvelope proteins, featuresofthe lipid bilayer, radial the independently folded domains of Gag. It shows two dispositionofthe Gag protein and other key features which represent challenges for the heterogeneityinparticle size and structure. First, the shapeare easily seen, determination of the three-dimensional COURTESYSTEPHENFULTER particles are not icosahedral.Rather they seemto be formed

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I

Grystallographyand the atomic anatomyof viruses Davidl.Stu ?rt,Jonathan M,Grimes, NickBurroughs & PeterP C,Mertens

David Baltimore in his 1976 Nobel Lecture millilitre, is simply treated as if it were a small protein and observed "The study of biologyis partly an exercisein subjectedto the battery ofcrystallization techniquesnow \X/e natural aestbetics, deriuemucb of our ileasure as standardizedin commercial kits. Whilst it is perhapsnot biologistsfron tbe continaing reahzation of how economica/,e/egant surprising that robust spherical virions crystallize, it is and intelligent are tbe accidentsof euolutionthat baaebeen main- astonishing that the crystals,held together by only a few tained by selection.A uirologist is amongsttbe luckiest of biologists flimsy non-covalent interactions, are so beautifully ordered. becaasebe can seeinto bis cbosenpet down to the details of all of its Naturally, since viruses are large, the diffraction from virus m.olecules.Tbe uirologist seesbow an extremeparasite fanctions crystals is far weaker than for single proteins. For insrance, usingjust tbemostfandamentalasputs of biologicalbebauiour. .." in the caseof the bluetongue virus crystals we have looked These words are made flesh by X-ray crystallography. \7e at, the number of repeating unirs acrossthe width of the X- use relatively soft X-rays (wavelength about 0.1 nm) that ray beam hasbeen as small as300, dramatically reducing the shine through our small crystals of virions, illuminating amplification of the signal upon which the method rests. every detail and allowing atomic models to be constructed For this reason,and becausethe number of diffracted beams 'spherical' of the exquisitely ordered symmetrical shellsof to be measuredincreases in proportion to the particle size, viruses.Knowledge of the three-dimensional positions of virus crystallography still presentstechnical challengesand the atoms gives a complete static view of the virus and progresshas been quite closely linked to the development of crystallography can, via the somewhat obscure B-factor, intense X-ray beamlines at synchrotrons. Several third indicate molecular flexibility. The results are objective, generation synchrotrons arenow coming on-line around the however, the personal aestheticsofthe crystallographer are world (the first of which was the European Synchrotron betrayed in the often riotous choice of colours for their Radiation Facility at Grenoble; Fig. 1) which present new representation.The first virus scrucrure was determined in opportunities to structural virologists. These machines 1977 by Stephen Harrison and co-workers at Harvard, and produce X-ray beams thousands of times stronger than over the yearca handful ofgroups around the world have can be obtained with conventional X-ray generatorsand built up a gallery ofover two dozen virion strucrures that allow the accuratemeasurement ofvery weak data. Further- cover hosts ranging from bacteria, through plants, to more, undulator beamlines are available on thesemachines animal's.The structures almost exclusively relate to non- which produce very nearly parallel beams,allowing more envelopedspherical viruses and a challenge for the future is to reflections to be resolvedon a detector ofa certain size.\With extend the technique to the lessamenable lipid-containing the technology now availableit is hard to seethe limit to viruses and the beautiful but complex machinery of some what can be achieved.For instance,we have recently solved bacteriophages.Crystal structures provide snapshotsof the the structure of the bluetongue virus core that contains virus life cycle which have profound implications for our almost 1000 polypeptide chains (Fig. 2). Even larger thoughts on many aspectsof their biology. Thus structure structures could be analysed,provided that they have a well hasbegun to at least partially illuminate questions of virus defined structure and provided there are dedicated micro- assembly, evasion of the immune response and cell biologists committed to making the many milligrams of recognition and entry. \Thilst crystallography has ledto pure virus required to analysesuch complex systems. some unexpected simplifications in our thinking about viruses(for instance, a recurring structural motif suggests Problemspots that most viruses studied to date may be related), it has also X-rays cannot be focusedsufficiently well to directly image shown the tremendous richness of invention that has been atomic structures. Instead the information in the beams of achievedby selecting accidentsofevolution. scattered X-rays is reconstructed with a computer to provide the image. The diffraction pattern obrained is a Smallcrystals / largeviruses seriesof spots which may be thought of as representing the A crystal of an organic compound or small protein contains scattering from the virus viewed through a grating. The many trillions of identical molecules whose molecular periodicity of these spots simply reflects the periodicity of structure may be visualized by amplifying the feeble the crystal whereas the brightness of the spots reflects the scatteringof a single molecule. Thus, when illuminated by a distribution of electrons within the virus. To solve a crystal nearly parallel beam of monochromatic X-rays, all the structure diffraction spots afe recorded from a complete set moleculesin the crystal scattertogether in certain directions of views of the crystal. Since X-rays quickly damage virus to give detectablediffracted beams.The concentration of crystalswe usually need to add together data obtained from the signal into such diffraction spots, according to rules put many crystals. Next the spots must be transformed into a forward by Bragg, allows relatively simple compounds to be map of the electron distribution in the virus. Here we analysedquite routinely in the lab. Virus crystallography is encounter a fundamental problem. The map is constructed somewhatmore complex but identical in its essentials.It from many componenr waves of different frequencies, turns out that the necessafyfirst step, that of growing amplitudes and directions (any objecr can be representedin crystals,is often relatively easyforviruses. A solution ofpure this way, as pointed out by Fourier). Each diffraction spot virus particles, at a concentrarion of a few milligrams per definesone such componenr, whosefrequency and direction

ffi trffiffiffiffi$#tuffiffiYIODAY VOL26/MAY99E Earlyachievements The seeming complexity of virus capsidscan mask their underlying simplicity. In 1955 \Tatson and Crick realised that 60 identical subunits could self-assemble to form a closed particle with icosahedral symmetry, ABOVE: is describedby the direction ofscatter ofthe diffracted beam thereby satisfying the biological imperative of genetic '$. Fig. IheEuropean Synchrotron and whose amplitude correspondsto the spot brightness. efficiency. Some yearslater Casperand Klug proposed that RadiationFacililyat Grenoble The beamline,abluetongue virusc'ystal To put the waves together to form the image we need to even more complex assembliesmight be made by relaxing andits diffractlan pattern are shown in know their relative phases(this is crucial - in-phase waves the requirement for exact symmetry (giving rise to the term clos e-u p, 'quasi-equivalence'). augment eachother whereasout-of-phase wavesinterferel). This can be achieved by breaking the PRODUCEDBYJ GRIiVES& D STUARI Unfortunately, when a diffracted beam hits a detector, only icosahedralbuilding block down into a number (T) of sub- OPPOSITEPAGE: its energy is recorded and all phase information is lost. The triangles, such that the shell is made up of 607 chemically $:ig.fl. Thestructure ofthe core of crystallographer hasto find another sourceof information to identical units. This explains the architecture of many bluetonguevirus The coiled dsRNA genomeisshown surrounded bytwo reconstruct thesemissing phases.Fortunately, there are now viruses but does not provide a mechanism by which the layersofprotein which have been routine techniques which, for viruses, usually start from exact size of such massiveassemblies is determined. This is partiallysiripped away forclarity rough phaseestimates derived from a three-dimensional exemplified by tomato bushy stunt virus (TBSV, the first PRODUCEDBYJ, DIPROSE J GRI[,,IES &D ST!ART USINGSOFTWARE PREPARID BYR, TSNOUF model. The model might be a crystal structure of a related virus solved), where the 7 = 3 arrangement of the protein virus, a lower resolution cryo-EM reconstruction or perhaps building blocks is exactly aspredicted by Casperand Klug a combination of electron microscopy and high resolution but where the architecture is defined by a pathway of X-ray structures of individual protein components. controlled conformational switching of the chemically identical subunits during assembly.This combination of Symmetrysavestheday quasi-equivalence and conformational switching has now The phasesdepend on the orientation and position ofthe been found in many virus structures. The TBSV structure model with respectto the axesof the crystal. The icosahedral also revealeda new type of protein fold, an elongated wedge symmetry of the virus provides us with a key not only to made from long strands of p-structure, often called a jelly unlock thesesecrets but also to refine our rough initial esti- roll since its strands are wrapped up asif the chain had been mates of the phases.Icosahedral symmetry consistsofa set of formed in the sameway as the American confection of that 5-,3- and 2-fold symmetry axesarranged in an absolutely name. This structure hasnow becomeavirtual trademark of fixed relationship to each other. If we look along a 5-fold viruses, being found in the capsid proteins of an enormous symmetry axis, the virus structure will repeat every36015 = range of viruses (although it is relatively scarce in the J2" around the axis. The sameis true of the scattering from proteins ofbacteria, plants and animals). The tempting (but the virus. It is a simple mattef, in a computer, to searchfor unproven) inference is that this revealsunsuspected ancient such repeatsin the measuredscattering and thereby lock on Iinks between plant and animal, RNA and DNA, and to the orientation of the particle. Once correctly orientated enveloped and non-enveloped viruses. Even ifthis is true it the model is moved systematically around the repeating remains a complete mystery why this structural signature is volume of the crystal to find the position that best predicts maintained over such enormous evolutionary distance in the observed scattering. Phasesmay now be calculated, very different structural contexts. Very different questions combined with the measured spot amplitudes, and an were answeredwhen the first animal viruses were solved in electron density map calculated.This map will be biased the mid-S0s; poliovirus byJim Hogle and human rhino- towards our rough model of the structure, adding noise to virus by Michael Rossmann. These structures immediately the image. Again icosahedralsymmetry helps us, since the led to a clear rationalization of many of the antigenic repeating crystal lattice cannot build in the icosahedral 5- properties of animal viruses and to an apparent resolution of fold symmetry. Inescapably,therefore, the virus particle has the conundrum of how viruses maintain binding sites for a additional internal symmetry. Since we have located these cellular receptor whilst evading the immune response.The symmetry axesit is a simple matter to impose icosahedral canyon hypothesis proposesthat receptor binding residues symmetry to clean up the picture. In practice we usea cyclic are concealedfrom antibody molecules within a crevice on procedure, using the cleaned up image to get better the viral surfaceand is still the subject of much discussion. phase estimates,which are combined with experimental amplitude measurements to give a new, improved image Movingup a gear:bluetonguevirus which is then subjected to further sanitization. Fortunately Most virusesanalysed crystallographically have beenaround computers are not easily bored and carry this process 30 nm in diameter. The publication last year of the structure through many cyclesto produce maps ofgreat clarity. of the 70 nm bluetongue virus (BTV) coreparticle (FtS.2)

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demonstrates that much larger assemblies can now be processof crystallization has laid down viruses in random tackled. BTV is a representativedsRNA virus and belongs orientations, blurring the image beyond recognition. The to the most populous family of such viruses, the Reouiridae. BTV core is very unusual in this respect and we can get a The coresof theseviruses acr as rranscriptional machines in fair idea of how much of the genome (20,000bp), made infected cells, holding their genome and rranscriptional up of ten unequal segments, is arranged. Unfortunately enzymeswithin a prorecrive shell so that dsRNA is never inappropriate blurring of the image limits the detail and revealedro the infected cell, eliminating any chance of a meansthat interpretarions are speculative.Nevertheless, by cellular response(such as the interferon response) to this taking rhe structure together with information from unusual nucleic acid. The strucrure suggesrs a compelling previous electron microscopicaland biochemical analyses hypothesisfor the assemblyof nearly l00O protein subunits. we canpropose a working model in which the enzymesform The core is made from two principal protein componenrs. transcription complexes under each of the 5_fold apices of There is a thin skin covering the genome and enzymes, made the protein shell. Thesecontain three components,which froml20 copiesof alargeproteinyp3(72), which assembles (working ourwards from the centre) unwind the genomic into an icosahedral arrangement via conformational dsRNA (a NTP-driven helicase),transcribe a messenger switching to yield a partern of subunits nor seen in other RNA sensecopy and cap it before it emergesfrom the core, virusesand not predicted by the theory of Casper and Klug. ready to initiate protein synthesis. \7e suspect that the ten This is clothed in 780 copiesof the protein Vp7(Tl3) in an RNA segmentsare nearly coiled around rhesetranscription arrangement that follows the theory of quasi-equivalence complexes, so that each segment is set up to run as an with greater precision than seenin other virus srructures. independent machine without tangling the enormously There is no need for conformational switching in this layer long piecesofdsRNA. since the vp3T2) subcoreacts asa scaffold upon which the Crystallography ofviruses hascome a long way in the last VP7(T1 J) layer assembles.Intriguingly there is evidence 20 years.Nevertheless, the strucrural basesof many of the from low resolution EM structures of other dsRNA fundamental biological functions are srill unsolved. These virusesthat the peculiar arrangement yp3(T2) of may be funcrions are often carried out by large multi-component conservedeven beyond the family Reoairidae.It is tempting protein complexes.Improvements in the molecular biology to speculatethat this reflects some fundamental involve_ and purification techniquesfor thesecomplexes, along with ment in the unique biology of these viruses. In most developments in synchrotron radiation, now provide a way crystallographic analysesof viral capsids there has been to tackle these difficult problems. rVe expect crystall_ little trace ofvisible strucrure for the genome. This doesnot ography to be in the vanguard ofstructural approachesto mean rhat such structure does not exist, merely that the the major functional problems in microbiology.

O Prolessor David Stuart and Dr Jonathan Grimes areatthe Laboratoryof Molecular Biophysics, RexRichards Building, South ParksRoad, Furtherreading Oxford OXl sQU Chiu, \7., Burnett, R.M. & O Dr Peter Mertens and Garcia, R.L. (editors) ( 1997). Mr Nick Burroughs are at Structura / B i oI ogy afVirus a. Oxford: Oxford Un iversiry the lnstitute for Animal Press. Health, Pirbright Gouet, P. e

ffi$ffiffi #ffi $#s"ffiwroDAYVOL 26l MAY99 E Nuclearmagnetic resonancg(N M R): keeping paCewith micrcbiology StephenMatthews

E, coli OI51 :H7 Aguide toN M R terminology 1|, The primary biological application of nuclear together with the enterohaemorrhagic (EHEC), haemorrhagic I*agnetic resonance(NMR) is in the structural a causeof acute gastroenteritis, WhatisltlMR? V study of small macromolecules in solution. colitis and haemolytic uraemic syndrome in humans, Certainnuclei (eg rH,13C 15N) interact Although NMR can reveal high-resolution structures, belong to a prevalent family of diarrhoeagenic enteric withhigh $rength magnetic fields These X-ray bacteria.EPEC and EHEC adheretenaciously to enterocytes canbe probed byirradiation withradio it provides information complementary to both wavesproducing aspectrum c0ntaining a crystallography and electron microscopy (EM). NMR in the gut and induce the formation of classicalsub-cellular seriesoflines Ihe frequency ofindtvidual facilitates rapid generation of a three-dimensional map, structures known asattaching and effacing lesions.These onthe spectrallinests dependent delineating the protein fold in a progressivemanner such E, coli strains produce a protein, known asTIR, which is chemicalenvironment ofthe be used to show clear functional transferred from bacterium to host cell, where it servesas a correspondingnuclei.Also, the relative that early data can protein Ihree-dimensionallocationof nuclei can implications. NMR can also be used to look at the dynamic receptor for bacterial adhesion via the surface bemeasured usingthe nuclear Overhauser processesinvolved in complex formation and folding. The intimin. This unique mechanism was only recently reported effect(N0E) enabling thestructure tobe main limitation of NMR is the sizeof the molecule under and it implies a prominent role for intimin in disease deduced investigation; the larger it is the slower it tumbles in progression.\7hat is more, a30'I kDa fragment of intimin (Int2B0) plays a central role in attachment and lesion Nuclear[|vethauser eflect solution, which in turn increasesthe efficiency of the Anindirect wayof measuring the NMR relaxation process.This manifests itself as a severe formation. Despite the clarity of the data presented on interactionthatoccurs through space as broadening ofthe spectrallines that eventually degradesthe intimin-TIR interactions, severalreproducible studies have nuclear theresultof coupling between resolution and efficiency of many NMR experiments. As a emerged that suggest a more complex mechanism for dipoles consequencean upper limit for molecular size has always EPEC/host-cell adhesion.These include the finding that LiquidcrystalNMR been associatedwith NMR and has therefore precluded its intimin will adhere directly to mammalian cells in the Asolution ofdisk-shaped micelles that usein sudies ofvery large complexes. absenceofTIR. inducesmolecular alignment ofa field macromolerulewithinthe magnetic ffi Usewith macromolecular complexes ffi lntimin structure andtherefore creates directly measurable It seemsremarkable that, in the light of the discovery of dipolarcouplings Recently, the technique has entered a new period of acceleratedgrowth, which should ensurethat it remains a intimin about 10 years ago and the recent acceleration 0euteration leading biophysical technique into the next millennium. of research into EPEC pathogenesis, the wait for a (perdeuteration) Thefractional orcomplete The increased use of deuteration together with novel detailed structural report has been so long. The very labellingofmacromolecules with for proteins and nucleic acids, and latest improvements have made proteins of up to 50 kDa deuteronsSub$itution ofdeuterons in labelling strategies have placeofprotons facilitates simplification the development of transverse relaxation optimized routinely amenable to sttuctural study by NMR and andimprovement ofNMR spectra spectroscopy(TROSY) have all extended the applicability accordingly opened the door for an NMR-based assault of NMR to much larger systems; molecular speciesin on the structure ofInt2B0. The new strategy has proved TR(lSY excessof 100 kDa are now tractable. Furthermore, liquid particularly successfuland has produced the first structural TransverseRelaxation 0ptimized (TR0SY)produces NN4R crystalline media together with the measurement of Spectroscopy HrO+tH spectrawith significantly nanower line- residual dipolar couplings enable structural information to widthsthan traditional experiments bythe be extracted accurately and easily without recourse to [13C]Glucose relaxation mutualcancellation o{two proton nuclear Overhausereffects (NOEs). NOEs allow the -0o/oD mechanisms, determination of interatomic distancesthat structuresare traditionally modelled from but these are notoriously imprecise and often difficult to acquire comprehensively. NMR can now provide information on the structure of DrO+tH sizeable molecules and, perhaps more importantly, the [13C]Glucose intricate details of large macromolecular complexes are -860/oD now attainable in solution. Although NMR does not compete with X-ray crystallography and EM for tackling huge structural problems, some major applications have ,,-**tJi/t-nd becomepossible. In addition, NMR still retainsits ability to generate structural data very quickly, which is often in the early design of new invaluable to the biochemist Drs+B ll,,l mutagenesisexperiments or the searchfor target molecules. i , llsc]GiucCIse iil\ri :i *g7o/os i'iiill ,ir ,'l i , ,'l,i ffiStudies of enteropathogenicEscherichia coli ',1,1il rll' i' "1l' This new potential for NMR has recently been illustrated ',i ,l I'l " t i'l the first structural study into the molecular basis of ',1i' i;" by r bacterium-host-cell interactions in enteropathogenic , Escbericbia coli (EPEC) infection. EPEC gives rise to , ,,1,,,,,,,,1 ,,' ,,,1,,,,,,,1,,, ,,,,1',' ,, 1,,',,, 8 6 persistent diarrhoea and is an important causeof mortality 10 1H amongst infants in developing countries. These organisms, (P'P't.)

E ffiffi$#ffi#ffi${Ffu#ffiY TODAYVOL26/MAY99 l

D2 ------>

D3 within full-length intimin and possibly a fourth. The IgSF OPPOSIIEPAGE domains in intimrn form an extended, articulated Iinker Fig.1. The preparation ofthe deuteratedproteins and its effect on the that protrudes away from the bacterium surfaceand confers 1HN[/R spectrum ofInt2B0 a highly accessiblethird domain for adhesion. THISPAGE LEFT The topology of the third domain is reminiscent of the C- Fig"f. Tertiarystructure ofInt2B0 and type lectins, afamily of proteins responsiblefor cell-surface proposedquaternary structure of carbohydraterecognition that includes animal cell receptors intimin, and bacterial toxins. Although Int2B0 lacks calcium THISPAGE BETOW Putativelg domains co-ordination, the similarity raises rhe possibility of ili*. *. Thethree structurally derived carbohydrate recognition in the function of intimin and modelsfor intimin-host celladhesion P|]0T0SC0URTESY STTPHEN ftilATTI]tWS implies three models for intimin-mediated cell adhesion. Fig. 3 showsthe three plausible models. In model A intimin binds a carbohydrate moiety that is attached to TIR. However, the rarity of bacterial glycosylation is inconsistent with this paradigm. Model B invokes a bipartite interaction,in which intrmin interacrswith TIR and a host- cell carbohydrate.Although studies showing that Int2B0 EPECmembrane and fragments of Int280 will bind cultured epithelial cells in the absenceof TIR add confusion to the intimrn-TlR glimpses within 6 months of expressingthe protein. story, the data do provide circumstanrial evidence to This has allowed the microbiologists concerned to support this model. Desprte this, we cannot rule out afinal redirect their researchefforts and make an impact from scenario, model C. Here the C-type lectin similarity is a biochemical perspective. Perdeuterated samples were incrdental and intimin interacts with TIR directly. produced,in which all the alphatic prorons were replaced The structural similarities of Int280 with animal by a deuteron and the amides were re-exchanged wirh intercellular adhesionmolecules are intriguing and provide protons.The standardNMR isotopesof nitrogen 1t5\) and remarkable insight into EPEC adhesion. This work is carbon (13C)were also incorporated. The removal of the probably the first demonstrarion of the usefulness of strong dipolar interaction involving protons drastically combined perdeuterarion/site-specific protonation and increasesthe short relaxation times normally associated NMR spectroscopystrategy. A good molecular under- with a molecule of this size.This improves both the spectral standing ofbacteria-cell interactions is crucial for targeted resolution and the sensitivity of many of the complex development of rational drugs and will have implications multidimensional, multiresonance NMR experiments for the design of novel drug delivery systems. that are necessaryto complete a structural assignment. Uniformly deuterateditN/l3C-labelled material is readily O Dr Stephen Matthews is a lecturer in the preparedby growing bacteriacontaining the recombinant D epartm e nt of B i och e m i stry, I m pe rial C o II eg e of geneof choicein a defined medium that utilizes 11NH4CI, Scrence, Technology and Medicine, Exhibition Road, ll3Clglucose and D2O as isorope sources.If protonared South Kensington, London, SW7 2AY glucose is used deuteration levels of up to B6 %ocan be TeL01 7 1594 5315; Fax01 7 1594 5207 achieved,but to accomplish full deuteration, a deuterated e- m ai I s.j.m atth ews@i c. ac. u k carbon source is required. Fig. 1 shows the effect of deuteration on the one-dimensional 1H NMR specrrum of Int2B0; the narrowing of the line widths and associated spectralimprovement are clearly visible. Further perdeut- eratedsamples, in which residuescontaining methyl groups arespecifically protonated, affordedsufficient NOE distance restraintsto facilitate the calculation ofa global fold. Fig. 2 showsa schematicrepresentation of the tertiary and quaternary structure of intimin. Int280 is highly asymmetric,approximately 90 A in length and built from three globular domains. The first two domains each comprisetwo p-sheetsandwiches that resemblethe classic immunoglobulin superfamily (IgSF). Tandem repeatsof IgSFdomains are ubiquitous within cell-surfaceadhesion moleculesand are responsible for a variety of molecular recognitionprocesses. Sequence alignment indicates the presenceof a third IgSF domain N-terminal to int280 d Uthat a Ramanspectrum Gantell the micrcbialecologist NozomiYtow

Microbial ecologists are mostly interested in the level ofnoise in the system and second,the heterogeneity of types of microbes present in communities and microbial communities means that the optical contribution their contributions to ecosystemprocesses. It is, ofeach cell is not unique, so that calibration is effectively therefore, desirable to know which are the predominant impossible. Another widely used optical technique is species in a community, their abundance and their fluorescencemeasurement, often in combination with laser- metabolic contributions. It is well known that most based cytometry, which can give information about the microbes in natural communities cannot be cultured in amount of fluorophore present. Although it can be used for the laboratory, at least with current techniques, and this continuous measurement, it has a similar restriction to that severely restricts identification of even predominant of molecular probes; if we are not sure what is there, we may microbes (ordinary bacteria or archaea)because identi- get no information or, even worse, we may get misleading fication classicallyrelies on responsesto specific media and information. \7e need a method with intermediate 'resolution' phenotypic expression under definite cultural conditions. that can tell us which types of molecules, rather Oligonucleotide molecular probes can help this situation, than which individual species, are present. Raman assuming that a microbial sample is available and we know spectroscopyallows us to do this. what we should be looking for. They can also yield inform- ation on the abundance of microbes and, with some TheRaman spectrum sophisticated treatment, can provide estimatesof metabolic A Raman spectrum is a set of very narrow spectral lines activity; hencetheir power astools in microbial ecology. emitted from object molecules when illuminated by an Although molecular probing is a powerful and incident light. The width of eachspectral Iine is strongly moderately straightforward technique, it still requires affectedby the spectralwidth ofthe incident light and hence samplesto be taken from the natural environment. Natural tightly monochromatic light sources,such as lasers,are communities do not exist inside laboratory flasks but as used. The wavelength of each Raman line is expressedas a components of ecosystemswith spatio-temporal structures. wavenumber-shift from the incident light, which is the The spatial and temporal structures of ecosystemsplay difference between the inverse wavelength of the Raman important roles in their dynamics becausespatio-temporal line and the incident light. The wavenumber-shift, not the heterogeneities can be driving forces for life processes,for absolute wavelength, of the Raman lines is specific to example a redox gradient in soil is a driving force for the particular atomic groups in molecules. microbial soil ecosystem.Periodic material exchangeby Raman spectrameasure the vibration statesof molecules tidal action is an example of heterogeneityin time. These which are determined by their molecular structure, spatial gradients and temporal changesin environments especiallyby atomic groups such as methylene, ethylene, can be generalized as spatio-temporal heterogeneities, amide, phosphate or sulphide. Most applications of Raman especially when these two elements are conjugated in a spectroscopy in biology are concerned with change in single ecosystem. Upwelling in aquatic systems and vibration states of macromolecules or related small hydrothermal vents are qp

E ffiffi"#ffi TODAYVOL26/MAY99 ResonanceRaman

chromophores with an absorption wavelbngth nearly matching the incident light, the efficiency of Raman scattering is considerably increased.This enhancemenr phenomenon, known as resonanceRaman scattering, is different from non-resonanceRaman scattering. Alrhough they differ in efficiency and application, they share the sameprinciple of non-elasticlight scattering.Non-elastic scattering is a process involving energy transfer, hence the energy of incident and scatered photons is different. Non-resonance Ramanscattering ABOVE: Since the energy of each photon is equivalent to its Similar Raman scattering also occurs even without Schematicdiagram comparing Raman scatteringwithfluorescence Each wavelength, non-elastic scattering can be detected as resonanceor absorption and is called, not surprisingly, 'non-fesonance bundleofhorizontal lrnesindicates the emission of light with a different wavelength from Raman scattering'. By contrast to resonance energystates ofa molecule, Lines in each the incident light. The energy difference of the emitted Raman scattering, which is only observed in molecules bundlerepresent vibration energy levelscorresponding toeach electron photon reflects the energy level in molecules, which is the which resonarewith the incident light, non-resonance energylevel, Dashed horizontal lines atomic group vibration within molecules in the caseof Raman scattering occurswith all molecules, excepr in cases indicatevirtual energy levels, Upward arrowsindicate theaction ofincident Raman scattering. By contrast, for elastic light scattering where Raman emission rs prohibited by a physical law, the 'selection photonsand downward arrows indicate it is momentum, not energy,transferred between photon so-called rule', which relates to the shape of emissionofphotons, Thelength ofeach and molecule, which results in a change in the direction molecules determining their vibrational modes. This non- arrowcorresponds tothe energy ofthe photonwhich isinverseiy proportional of the photon, i.e. reflection and refraction. This can be specificity means that non-resonance Raman specrroscopy tothe wavelength ofthe light The used to provide information such as the shape of whole can be used as a general tool to chancterize and to quantify horizontalspacing between arrows indicates objects as a result of the phase interference between organic matter in the natural environment. All natural thetime between upward anddownward pr0cesses, Anelectron scatteredphotons. organic molecules contain either methyl or ethyl groups, so inthe molecule isexcited bythe Resonance Raman scatrering may sound like fluor- estimation of the concentration of these groups gives a absorptionofa photon: ihefluorescence photonisemitted after arandom delay, escence,but it is a completely different process.Fluorescent measureof the organic carbon concentration. Simultaneous Inthe case of both resonance andn0n- light is generated after absorption and re-emission of recording of Raman bands corresponding to methyl/ethyl, resorlanceRaman, theupward and a photon by the chromophore, but resonance Raman amide and phosphate groups provides a fingerprint of the downwardpr0cesses musttake place simultaneously;forthat reason, itis emission is induced without the absorption of a photon. organic moleculespresent. The generality of non-resonance referredtoas a tw0-ph0t0n pr0cess, They can be practically distinguished; when the wavelength Raman scattering means that it can provide a simultaneous of incident light is changed within a comparatively record of a wide range of molecules.\7hen we find a spectral wide tolerance fluorescence spectra are not affected. The pattern indicating the existenceofa molecule of interest, we wavelength (i.e. absolute wavenumber) of a Raman line, on can then apply more specific methods to obtain grearer the other hand, varies with that of the incident lighr to detail. This is perhaps the greatest porential that rhe tech- keep the Raman shift constant. Also Raman scattering nique has to offer microbial ecology. It also provides the induced by a laser light gives much narrower spectral lines opportunity for a continuous monitoring method to give compared with the broad spectrum of fluorescencl; a spatio-temporally continuous view, which is highly the former is of the order of spectral band width of the desirable for understandinq the nature of microbial eco- incident light (commonly less than 1nm with currenr systems. lasers),but the latter is 10 nm or more and is not affected by the band width of the incident light. Using these lncidentlight differenceswe can distinguish, for example, between Resonanceand non-resonanceRaman scattering differ carotenoids and chlorophyll in phytoplankton cells in not only in specificity but also in sensitivity. Application of uiao, without any chemical treatment. Carotenoids can non-resonanceRaman scattering is limited by the far be detected as spiky Raman lines beside the broader weaker intensity of scatteredlight which arisesfrom the fluorescencefrom chlorophylls. This is an unexpected nature of Raman scattering. Unlike absorption, Raman result,considering the relative abundanceof chlorophyll emission is the result of an interaction between an incident and carotenoidsin phytoplankton cells. Either the energy photon and the molecule, which is a much rarer event. This transfer between chromophores or the intracellular results in a much lower intensity with rhe same intensity structurein which thesechromophores exist musr suppress (flux of photons) of incident light. Furthermore, rhe fluorescencefrom chlorophyll. Indeed the chlorophyll fingerprint region of organic molecules in Raman spectra fluorescence of solvent exrracts from phytoplankton is rather close to the wavelength of the incident light. cells makes detection of the carotenoid Raman band Conventionally, tandemly aligned double or triple specrro- difficult. Thus, resonanceRaman spectroscopyenables such meters have been used asfilters to eliminate stray incidenr 'optical'extraction of molecules. The choice of incident Iight. Sensitive detectors and long exposuresare necessary, laser wavelength determines which molecules will be not only becauseof the weaknessof Raman emission but excited, and hence we can differentiate molecules of also due to optical losses in tandem aligned multiple interest.

ffi $ffiffi ffi ffi$sffi ffiYTODAYVOL26/MAY99E spectrometers. For longer exposures,thermal background noiseof the detector must be reduced and electrically cooled charge-coupled device (CCD) detectors are now commonly used for Raman spectroscopy.Incident light sourcesmust have very narrow bandwidths becauseRaman lines carry over the bandwidth of incident light, and a broad spectrum of incident light reduces the spectral resolution of Raman spectra.The light sourcealso must have high intensity and be well focusedto optimize efficiency of the optical systems. For thesereasons, lasers are commonly used aslight sources in modern Raman spectroscoPy.

Fieldapplications Raman spectroscopy has been largely used in laboratories with a specific interest in molecular vibration, so high- resolution spectrophotometershave normally been used. Spectrophotometerswith longer optical paths have been preferred becausethese enable better spectral resolution. A longer optical path, however, results in greater optical lossin the system so demandslonger exposureand a more intense light source,which again meansa lasersource. These problems havemade the application of Raman spectroscopy in field researchdifficult. Smaller optics are preferable for field use not only for portability but also becausethey are brighter, enabling shorter exposuretimes (i'e. more data), and consume less power (the light source and the CCD cooler are the main power consumersin Raman spectro- scopy). Field applications sometimes do not require the high spectral resolution demanded by the specialist laboratory and hencewe can reduce the sizeofthe optical system by restricting the spectral resolution within an acceptable range.Nowadays improved optical elements are commercially available, although some of them are restricted for military trse, which permit the field application of Raman spectroscopy.Higher sensitivity resonanceRaman spectroscopy would also expand the arcaof application by facilitating the detection at lower concentrations of the object molecules with lower power incident light and with shorter exposuresto improve the time resolution of the process.Combination of resonance Raman spectroscopy and fluorometry would give another approachto quantifying biological pigments.

Conclusions from the physics world Furtherreading Raman spectroscopy has emerged laboratories Ferrano,J.R. & Nakamoto, and has been applied in specializedbiophysical K. (I99 4). lntroductory Raman as a technology to investigate molecular dynamics. Specnu npy. London: Academic Improvements in each component technology are cfeating Press. an opportunity for wider application, including microbial Laserna,J . (editor) ( 1996). J ecology. Raman spectroscopyis now gaining the ability to ModanTecbniquesin Raman be usedfor general field observations. Spearu npy . Chichester:John \filey&Sons. Turrel, G. & Cortset,J. O Dr NozomiYtowis basedin thelnstitute of (editors)( 1996). Raman BiotogicalSciences, University of Tsukuba,Tsukuba, Microscopy. D eueloPments and lbaraki305-8572Japan Applicat i ons.London:Academic Press.

E ffi&ffiffiffiffi&ffituffi ffi TODAYVOL26/MAY99 Bacterialclassification and taxonomy: a,primertf,or the new millennium HowardGest

do not The notion that a single molecular marker, indeed hydrolyse gelatin, but thesereincarnations of its 165 rRNA sequence,can serveto decipher the reflect appreciable advancesin an understanding This example evolutionary phylogeny of bacteriahas apparently basic features or evolutionary relationships. into the research led to significant effectson the minds of many investigators' indicates how confusion is introduced information retrieval' It These effects include: (a) a generalamnesia about the long Iiterature, text books and computer history of thought and debate on the classification/ is alreadyhappening. taxonomy of bacteria, (b) some confusion about the distinction between actual bacteria and what can be called Genusand species 'virtual An authority computer bacteroids', (c) a mental void on the long, How are bacterial generaand speciesdefined? of SystematicBacteriology. rich and important history of research into microbial on this matter is Bergey'sManual abit fuzzy, especially that of nutrition, which led to the elucidation of many basic The definitions are, in fact, principles of biology and cell biochemistry, (d) belief in new genus. From the M anuaL. 'discovery' myths such as the recently trumpeted of a 'uncultivable' "Tbe usually a auell-definedgroap that great diversity of free-living, microbes as Genus: bacterialgenas is genera,and the thorough ducriptions indicated by molecular biological probes' and (e) is clearly separatedfromother Bergey'sManual exemplify tbe implantation of the misconception that the classificationof of generain the 1984 edition of group is usaally known. Howeuer, bacteria should be largely, if not entirely, based on depth to which tbis taxonomic 0n the definition of a genusin evolutionary phylogenY. thereis sofar no generalagreement subjectiuity is inuolued at the The immediate inspiration for this article was a sentence bacterial taxunnrny,and consid,erable perceiuedto bea genusby oneperszn may used by Sydney Brenner (1997) in an imaginary letter sent genusleuel. lndeed, what is ThcChirn-pansg by another systematist"' to a mythical nephew, namely "l can't seetbe woodfor the beperceiued as beingrnerelya species 'wood', phylogenetictrees". To help see the I have selected " may berqgarded as a collectionof How items from the extensive researchliterature that illustrate Species: A bacterial species in commonand dffir considerably l}0 the problems encountered in the historical development of strains that sharemany features ofa speciais designatedas tbe type bacterial classification and taxonomy schemes. This from otberstrains. ..Onestrain Tert 'primer' of the speciesand W is offered as an elementary guide, as we enter the strain; this strain seruesas tlte name-bearerstrain ilhe i.e. the refaencespecimen next century, to the somewhat chaotic status of this is tbepermanent exanple of tbe speciu, for great importancefor classification at tsrrrdds important aspectof microbiology' the nam.e.Tbe typestrain bas Fnrom the speciesleuel, becaasea speciesconsists oftbe type strain and all The Thesituationin 1946asviewedbyG.B.van Niel otberstrains tbat are consideredto besfficiently similar to it as to . ." In 1946, thegreat microbiologist C'B. van Niel published a warrant inclusionwith it in tbesqecies. Ftowers 'The ,Amd thoughtful essayon classificationand natural relationsbips of bacteria'in which he reviewed the history of earlier work NumericaltaxonomY 0tlhen an application ofthe aimed, in part, at developinga stableand generally accepted In 1953, Sokal and Sneathdescribed Woodauts taxonomy in which as many 'Verses nomenclature that would eliminate duplication or multi- Adamsonian approach to possible are used and given /{mdn&ustmttons plication of names for the same organism' He emphasized diagnostic characteristicsas relationship between organisms tsgRohwk Wtt\tams Wood that even if we knew the phylogenetic relations among equal weight. The degreeof number of similar classification basedon such relations would not was consideredto be a function of the bacteia,a 'similarity as a coefficient.' necessarilybe the best or most efficient for determinative characteristicsand is expressed has been demonstrated purposes. The utility of numerical taxonomy in a number of studies. Sneath reviewed the 3O-yearhistory Ghanging namesof bacteria of numerical taxonomy in 1995 and concluded that "Numerica/ senseis tbe greatestaduance in Although determinative keys are very important in taxunllny in tbe broad perhapsLinnaeus. lt bas stirnulated practical matters (for example in medical microbiology, systentaticssince Darwin or numerical pbylogenetics, public health microbiology and plant pathology), this tends seueralneu areas of grotutb, including yrny, r i cs and nurrter i ca I i dentifi cati on to be forgotten by those probing evolutionary relations ruoI ecuI ar t a x 0n morph ornet does not assumephylo- "' using molecular markers. The latter press for revised Even though numerical taxonomy that closecorrespondence taxonomic schemesand this inevitably leadsto proposalsfor genetic relationships, it is obvious phenotypic characteristics has changing namesof bacteria. of a large number of Particularly egregious instances of name changing something to sayabout genetic connections. have afflicted the anoxygenic photosynthetic bacteria (1970) group. Example - The purple photosynthetic bacterium Cowan'scomments on taxonomy " existsltetween Lewis Carroll's Rbodocystisgelatinosa isolated in 7907 was renamed A bitberto undetectedsimilarity and bacterial taxonomists in Rbodopseudomlnasgelatinosa in 1944, redesignated Alice and taxonomists, can - and does- driue taxonomiststo a Rbodocyclusgelatinosus in 1984 and in 1991 the name particalar...taxlnlrny . . " note: this paper was Rubriuiuax gelatinosuswas proposed. The bacterium does tlpsy-taruy Vonderland. lAuthor's

trI ffi HS*&HISffi &VrcDAYVOL 26IMAY99 basedon a seminar Alice inTaxonomylandattheUniversity of ualidity of adjacent taxa was being questioned.Many generaare Maryland, 5 May 1969.). . . "lt is surprisinghow rnanyso-called beterogeneousfrom tbe molecularuiewpoint and tbis would imply microbiologistslook upontbe scbemes published in BergeylManual that all tbeir speciesrnust bestadied beforedeciding on tbe new ( 1923-1957 ) as if theywere not only usefalgeneral classifications disposition of the genul This still leauesananswered the questionof of bacteria, but onestbat baue receiueduniuersal approual, botb on boutbornogeneous tbe species are." earth and in beauen.I ant assuredby my nlleagau that approual of lflheWffiHem, The Llclhrcn. Bergey'sManua/ is not uniuersal,euen on eartb; I am notyet ableto Moreon moleculardata judge Lrchens,regardlessofconyenlions, its receptionin beauen.. ." In 1994, Murray and Schleifer pointed out that the Ixistin onl!turo dirrensions, Cowan pointed out that elaborate rules have been international nomenclature code " is not able toprouide sensible fi ti{erestricted to a plane. stipulated in codes of nomenclature in the attempt to regulation of nomenclaturefor new taxa defined by uery limited 0niochs and stones a sieenish slain, regulate the formation and names,"but tbesecodes would data, nucleotide portion Theulive upon the sim-pleSt {.rre. use of suchas a sequencefora small of thegenome. Adfop qf deru, a brealliof air. deligbt tbe bearts of lawyers becausethey are t00detailed and try to Tbe constructorsof tbe original code(1957) and theJadicial Contiaitthern urith the ireeduHen. caterfor all euentualities.ln the euent,they are confusingand self- Commissionconsidering the 1976 and 1990 reaisionsdid not ffndher lnost careless reeindn. confuadicting.. ." 0r act upln tbepossibilities molecular descriptionand Sheshuns the banen slone! dnd rocks. ' foresee for flndthrives upon the Sarbase bor. "Tbe Bacteriological Code {i.e., International Code of typification of prokaryotesthat werenot yet cultiuable. As a resalt, Nomenclatureof Bacteria] sbould besinrp/ified by deleting the formal namesare beingproposed for uncultiuated prokaryotestuhose Rulesand Recornntendations,It sbould consistof Principles, and uniquenessis defined only by uery lirtited cbaracteristics, such as discretion sbould be giuen to bacteriologists to apply tbem dffirencesin a molecularsequence. . . intel/igently." The magnitude of the problem that Cowan A noael sequenceisolated from nature merely indicates that discussedis indicated by List no. 22 published in the tberemay bea unique organismin tbe enaironrnent.Howeuer, one lnternationa/Journal of SysternaticBacteriology (36, 1985), bas to take into considerationtbat sorrtetirnessequencing and/or which contains 44 new names, new combinations, amp/ification errlrs simulate a noue/sequence, suggesting some synonymsor revived names. intraspeciesdiuersity, or tbat formations of cbimeric sequencesmay bepossible. Moreouer, tbe possibility tbat tbe sequenceuas retrieued Exampleof a rule from the Code from cell-fru (naked) DI'{A cannot beexcladed, and it ntay haue "Rule 56b. A conseruednarne (nonten conseraandum) is a name originated froxt an organism not originally growing in the wbicb rnustbe used instead of all earlier synlnllns and homonyms, exarninedbabitat. . ." 'environmental Note 1. A conseruednarne (nomen conseruandum) is conserued In fact, it was recently demonstrated in an against a/l otber namesfor the tAxln, whether theseare cited in tbe ecology' study, that RNA sequence data supposedly correspondinglist of rejectednames 0r nzt, so long as tbe taxon indicating the presence of certain bacteria in natural concernedis not united with anotber taxon bearing a legitimate sampleswere due to contaminating 165 rDNA introduced name.ln tbe euentof union or reunionwith anotbertaxon, the in the exquisitely sensitivepolymerase chain reaction. earlier of the two competingnarnes is adopted in accordancetuith Ralu 23a,b." Concludingremarks The intent of this rule, to stabilize nomenclature, i3 The assumption that our current knowledge is sufficient to excellentand is quoted here only to illustrate the quasi-legal waffalt new, presumably'finaI' , names for many genera and (sometimesconfusing) language of the Code. speciesis obviously questionable andarrogant, and evokes Cowan's admonition: "lt is ofteneasier t0 createa newgenus 0r ' Sneath's1989 assessmentof the utilityof speciestban to do tbe cornparatiaework necessaryt0 pat dn organism molecula r seq uence markers i n classification into its rigbtful place in an existing genusor species.Tbe temptation andtaxonomy to designated. new genus or speciessbould beresisted." Obviously, "Amajor dfficulty with curcentlyauailable molecularsequences is as knowledge advanced, numerous name changes were thefax tbat theyare only sanrpla of relatiuely small size, Sam.pling proposed and many were reasonableand useful, for example enor will tbereforecontinue to dominate tbepicture. . . the change from Streptlclccxtslactis to Lactococcuslactis. )ne area that is now being explored is the use of molecular During the past two decades,however, the notion that a 'signatures', - small sub-sequencesthat are cbaracteristicofuarious single molecular marker can accurately reveal evolutionary bacterialgroupings. Tbeir ualue will dependconsiderably on bow phylogeny has driven a deluge of premature name changes. clnstant tbesesignatures a.re witbin tbe newly defined bacterial Since recent researchsuggests that microbial evolution was taxa. At presenttbere has beenno detailedanalysis oftbis, tbougb far more complex than commonly supposed,and probably somewitbin-taxon aariation is eaident.. . involved extensive lateral gene transfer, conservatism in Thecartoons onthis page and the Anotber morepragmatic questionis bowfar we can safely reuise nomenclature changesseems well advised. oppositepage afe lakenfuon'How to bacterialclassifications on present sequence data. ln many of tbe Carl Linnaeus originated the systematic classification of lell theBirds fron tlteFlowers and }therWoodcuts'by Robert Willjams papers earlier on rRNA, strain nuruberswere seldont giuen, sowe do plants and animals.ln 1737 , before microbiology becamea Wood(Dover Publications 1959; notknow whicb weretype strains. Most tr.,orkersexamined only a science,he said "Vhat difficulty basbeen caused to botanistsfrom originallycopyright by Dodd Mead & singlestrain of a taxon sucb as a genxls,yet tbe analyseswere tbe reuiual of tbe sciencesdown to tbepresent day by tbe inuention of Co1 917). REPRODI]CEDWITHTHE PIRMISSION OFDOVER displayd as representatiueof the entire taxln - szmetirteswben tbe new.narrtesis knlwn t0 eaeryonewbobas bandled the sabject." Alas, PUBLICATIONS

ffi *ffiffiffiffi$#e#ffi ToDAYVOL26/MAY99E RIGHT; 2ndWorkshop inMolecular Biology In1949 while still agraduate student i'-ii. ProfessorGestmade the unexpected ','.1 28December 1998-9 January 1999 discoverythatarloxygenic photosyntheticbacteria fixmo ecular UniversityofMedicine and Pharmacy, HoChi Minh City, Vietnam nitrogen,Heand his colleagues have isolatedandcharacterized anumber I RobertE.Glass ofnew species ofpurple and green anoxyphototrophsincludingthe Thistwo week courseconsisted of both practicalsand remarkablebacterium Rhadospirillum lectures.lt wasdelivered in English,with dual translations. centenum.Thelatter was isolated in 198/and giver rhe soec es nare iT Sevenpeople f romthe UK andone personf romThe commemorationofthe fact that it was Netherlands/- | oarticioated. The U K co-ordinatorwas Dr Simon drscovered100 years after the f rst Cutting(Schoolof Biological Sciences, Royal Holloway isolationofa photosynthetlc bacterum Universityof London)and Dr PhamHung Van served as the inpure culture (Rhodaspirlllun Vietnamco-ordinator. rubrun).When grown on agar, Thecourse aimed to introducemolecular biology and its R.centenun cells produce ritlmer0lls associatedtechniques to Vietnam,which is a developing lateralflage llaand the swarming inf rastructure colones exhibit phototaxis (thefirst countrythat contains a soundacademic microbiolo gy today is faced with this old problem. (e.g. knownexample insuch organisms), In establishedby the French threePasteur Institutes). "Tbosewbo cannot conversation,Professor Gestrefers to Santayana's190) observation is timely: AlthoughVretnam has a goodbackground in the natural over'zealousbacteria taxonomlsts who remextberthe past are condemnedto repeatit," sciencesand immunology, it has little understanding of molecularbiology and howthis can be appliedto research word like to change thename ofR There is every reasonto believe that ascurrent genome centenu m as'taxonomic prrates', anddevelooment, sequencing projects mature and expand, we will be in a The43 enrolledstudents came from all overVietnam (in reality much better position to evaluateorganismal relationships manymore people attended the lecturesthan justthose who Sources and deal with classificattonltaxonomy schemes more wereenrolled). The enrolled students sat and passedan were a certificate Brenner,S. (1997). Loose Ends, effectively.In the meantime, readersare referredto a very examset bythe organizersand awarded indicatingtheir successf ul attendanceon the course.Each p. 57.London: Current Biology. useful summary by R.G.E. Murray (1998) of current wasgiven an extensivecourse manual containing details of (1970). Cowan,S.T. Heretical problems and proceduresin dealing with taxonomy and allthepractical classes and handouts for allthe lectures. taxonomyfor bacteriologists. nomenclature of bactena. Duringmy week on the J GenMicrabiol 61,145-154. Attention is also directed to a thoughtful review by courseI gavesix 1'5 hour Krieg, N.R. & Holt,J.G. Palleroni(1997) that discussesthe limitations in using only lectureson geneexpression (edit<-rrs( 1984). B crgel': ) andits regulation. I also Overviewof geneexpression molecular datafor analysisof prokaryote systematics.On ManuaI afS y s tema ti cB acterio I o gy, attendedseveral ofthe regulation rVilliams Vol.1. Baltimore: & the brink of the new millenium, the significanceof 165 practicalclasses and helped DNAtranscription Wilkins. rRNA asa ma;'or taxonomic criterion is receding. At the withthese as well as dealing RNAtranslation R.& Rivera, Lake.J.A..Jain, same time, recognition of lateral (horizontal) gene transfer withquestions arising from Generegulation M.C.(1999). Mixand match in boththe practicalsand asan important element rn prokaryoteevolution is gaining thetree of life.S cience 28J, lectures. momentum (Lakeet al., 1999). 2027-2028. Thestudents were a fantasticbunch of oeoole.I foundthem Murray,R.G.E.(1998). incrediblykeen to understandand learnmolecular biology. Taxonomyand nome nclature. O Howard Gesf rs Distingjuished Professor Emeritus Oncethe initialshyness of meetinga new personhad worn -51 ASM N ews54 (D ec),669 0. at lndiana University, USA, where he works in the off,they were morethan readyto come up and ask questions afterthelectures and durrng the practicalclasses. I really felt Murray,R.G.E. & Schleifer, Photosynthetic BacteriaGroup. He may be contacted K.H. (1994). Taxonomic notes : thatthe studentsgot a lotf romour presence, both in terms of at the Department of Biology, Jordan Hall, lndiana aproposal for recording the the contentof the courseand the chanceto speakscientif ic propertiesofputative taxa of U niversity, Bloomi ngton, l N 47405, U SA English. procaryotes.IntJ Sys t Bacterio I Tel.+1 812 8559612 44,]4J16. e-m ai I hg e st@s unflowe r. bi o. ind i an a.ed u Conclusions Palleroni,N.I.Q997). I felt that the coursewas veryworthwhile, lt was clearthat Prokaryoticdiversity and the the studentswere learning a considerablebody of molecular importanceofculturing. Antonie biologyf romus. This was indicatedby the levelof the LeeuuenhoekT2,S-19. questionsas the courseprogressed and their performance Sneath,P.H.A. (1989). inthe writtentest, Since the studentscame from allover Analysisand interpretation of Vietnam,they will be ableto takethis knowlecl^o henlr rn sequencedata for bacterial a numberof differentdepartments. systematics:the view ofa O ProfessorRobert E. Glass works in the lnstitute of numericaltaxonomist.,lyrl Genetics, School of Clinical Laboratory Sciences, QMC, ApplMicruilt / 12. I 5-J I. Clifton Boulevard, Nottingham NG7 2UH Sneath,P.H.A. (1995). Thirty Tel.011 5 970 9226; Fax 01 15 970 9906 yearsof numericaltaxonomy. e-m ai I robe rt.g Ias s@n otti n g h am.ac. u k SystBic,l44,28I-298. VanNiel,C.B .(L946). Theclassification and natural relationshipsof bacteria. ColdS pring Harbor SyaQ Il, 285-70r.

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International DevelopmentFu nd reports

Throughits lnternational Development Fund, SG M isactive in disseminating informationabout microbiologyto scientists in developing countries, Here recent recipientsof awardsdescribe how Society sponsorship h-as been used to advancethe knowledgeofmicrobiologists inSouth EastAsiaandtosponsorscientistsfrom other partsof theworld to attendan internationalconference in the U K.

frk 3rdInternational Conference onAnthrax rLi ffi f* 7-10September 1998,University ofPlymouth W af #fr FS I LesBaillie *4 ffi f# ffi r* The conferenceattracted approximately 1 70 delegates representingall four corners of the worldwith the notable exceptionof Antarctica;apparentlypenguins do notcatch anthrax,Through the generoussupport of the Societyfor GeneralM icrobiology we wereable to sponsorthe attendanceof scientistsf rom suchdiverse locations as Cuba,India, Russia, Turkey and Columbia. Althoughit was a singlesubject conference, the presentationsfilled three full days and were divided into sixmain themes: Natural ecology and global incidence, Detection,ldentif ication and classif ication, Structure and function,Molecular biology, Pathogenesis and vaccines. Inall 36 oralpapers and 54 posterswere presented. Insupport of the scientific programmethere were a numberof socialevents, notablv a visitto the NationalMarine Aquarium,and the conferencedinner at whichdelegates ABOVE: wereencouraged to meet,discuss their work and makenew TrainingCourse onSRSVVirology Participantsonthe SRSV Virology contactsin spiteof the bestefforts of an excellentjazz band, 11-24November 1998,Beijing TrainingCourse held in Beijing China Theseinformal opportunities were of particularvalue to workersnew to the f ieldwho hadthe chanceto speakto I BinleiLiu BELOW: manyof the 'oldhandsi DrBrnlei Ljugiving alecture,

Thestated aims of the conferencewere: InNovember 1 998 l conductedatwo-weektrainino course O to bringtogether the keyworkers in the fieldof anthrax in Beijing,China. The course was jointly organized dythe qnd lnstituteof Nutritionand Food Hygiene, Chinese Academy of rpqearr-h tn rorriorarnrnnrAqq tnLv uuLv,deto sr rv PreventiveMedicine, Beijing and the Departmentof O to createa criticalmass which will leadto the formationof MolecularMicrobiolooy, University of Southampton.lt newnetworks, the exchangeof ideasand stimulate new includedthe introduciibnof recentadvances in studies on avenuesof research smallround structured viruses (SRSVs, or Norwalk-like Inthe light of the feedbackthat the organizersreceived viruses)and the applicationof the immunodetection (ELISA) duringand since the conference,it wasfelt that these aims techniquesfor SRSVsin China. wereachieved. SRSVscause acute, explosive diarrhoea and,/or vomiting, Forthosewho were unableto attendit maybe of interestthat and havea highassociated infectivity, giving rise to rapid allthepresentations were recorded on video,copies of which secondaryspread. Food and waterare majorsources of willbe made avaiiable. In addition, the organizingcommittee SRSVtransm iss ion. S RSVshave a worldwided istrib ution intendsto publishthe proceedings, and outbreaksof acutegastroenteritis have been reported t in manycountries, Although China has the largestpopulation Forf urtherdetails of the conferenceplease contact me. inthe world,no SRSVoutbreak has ever been reported and O Dr LesBaillie was the Conference Chairman. He is investigationsof SRSVepidemiology and seroepidemiology basedat DERA, Building 384, CBD Porton Down, havenot been conducted there. SalisburySP4 0JQ Therewere 14 participants,including staff, Masters and PhD Tel.019B061 3881 studentsselected from the Instituteof Nutritionand Food Hygiene. Professor Xiumei Liu, Director of the lnstitute, deliveredan openingspeech on the importanceof studyon SRSVsin China. I gavelectures on the molecularbiology of SRSVand its detection using RT-PCR and ELISA. The participantsperformed ELISA experiments following my demonstrationof thetechnioue, Traditionally,SRSV detection has been performed by electron microscopy.However, such expensive equipment demands the dedicationof a skilledoperator and unfortunatelythis is not availablefor routrnediagnostic virology in developing countries suchas China.ELISA offers a cheapalternative technology. SRSVsare ihe mostcommon group of virusesinvolved in food-bornecontamination The development of ELISA technology for these viruses is a timelyand important step forwardthat is particularlyrelevant to the interestsof the Instituteof Nutritionand Food Hygiene. O Dr Binlei Liu is currently a Career-Track Postdoctoral Fellow atthe Department of Molecular Microbiology, Medical School, University of Southampton, SOI 6 6YD Tel.01703 494941 ; FaxOl 703 774316 [email protected]

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A previewof Transport is an essential component of our into and acrossthe endoplasmic reticulum (ER) membrane thetopics to be lives. Yet cells display a dexterity in speed of to the ER lumen. The hydrophobic N-terminal signal discussedatthe conveyance, complexity of the variety of peptide on the exoprotein is recognizedby the Secsystem. In SGMMain molecules carried and specificity of carriers that makes many Gram-negative bacteria,Sec-dependent translocation the traffic problems of the M25 look trivial. A major servesto present a subsetofproteins to the Type II secretion SymposiumHow problem in both casesis getting to the right place at the machinery, which is then responsible for the second Do Molecules right time. (terminal) transport step across the outer bacterial CrossMicrobial In eukaryotes, some proteins are destined for particular membrane. Type II secretion requires some 12-16 proteins. Membranes? organelles (mitochondria, chloroplasts, peroxisomes, Filloux will discuss the composition of the proteins in the 'patch' attheUniversity ' lysosomesor the nucleus), some of which have multiple Type II secretion system and speculateson how the of Leeds,7 -B compartments. Others are retained within the general secretion signals of exoproteins are recognized by the September1999 secretory pathway (endoplasmic reticulum and Golgi), machinery. Proteins can be delivered to the SecYEG exported to the plasma membrane or secreted from the translocaseeither via chaperones,most notably via the cell. Even for the relatively simple prokaryotic cells, the export-dedicated chaperone, SecB, or through their problem of delivering molecules to the right place at the interaction with a signal recognition particle (SRP). In right time is not trivial. In a Gram-negative bacterium, eukaryotesa cytosolic SRP binds the hydrophobic signal macromolecules may be destined for the inner membrane, peptides of presecretory proteins as they emerge from the periplasm, outer membrane or the external medium. ribosome and delivers the nascent polypeptides to the No previous SGM symposium has focused entirely translocaseat the ER membrane. In their review High on microbial transport, although individual papers on and colleagueswill discuss the evidence for a bona fide transport of small molecules (late 1970s), protein secretion SRP-dependenttargeting pathway in E. coli. mechanisms (1989-1991) and, more recently, protein By contrast Typ" I and Type III systemsinvolve one-step transport in relation to host infection (1993-1997) have mechanisms for protein translocation. Type III systemsare been written for SGM symposia. The wealth of molecular found inSbigella, Salmonella,certain E, coli strains, Yersinia information on transport systemshasJed to an improved and plant-pathogenic Pseudomonas,Xanthomonas and understanding of the shared features of transporg in Erwinia spp. These systems comprise a sizeable set of prokaryotic and eukaryotic cells and the complexity of proteins capableof delivering a number of virulence factors machinery required to ensure the safedelivery of molecules into mammalian or plant host cells. Schneewind will review to the correct location in an active state. Some of the many the Type III secretion machinery of the pathogenic current interests in microbial transport are: the nature yersiniae.Some of their proteins are directly injected into of transmembrane channels and the regulation of their the cytoplasm ofthe eukaryotic host cell (so have to cross gating; the structure and mechanisms of protective three membranes), whereas others are secreted into the chaperone proteins; and the mechanisms for ensuring surrounding medium, or remain bound to the surfaceof correct targeting, modulating protein-protein interactions the bacterium. At least three of them require dedicated and controlling ligand sp".ifi.ity. Hence a symposium on chaperonesfor successfultargeting. Type I systems utilize transport of molecules acrossbiological membranes seems a periplasmic ABC transporter (ATP-binding cassette) timely. of which the cr-haemolysin of E. coli is the best known example. Typ" I systemsgenerally secreteonly one or a few Prokaryotic protei n secretion exoproteins, and these are Bacterial membranes provide essentialbarriers between the recognized as substratesby inside of the cell and the external medium. Yet protein the ABC protein exporter, secretion is essential for secretion ofvirulence factors and largely by virtue of the extracellular enzymes, and also for the assembly of cell secondary structure of their appendageslike pili and flagella. Other proteins have to be C-termini. The dynamics integrated into the inner and outer membranes or exported of the assembly of this to the periplasm. Gram-negative bacteria have evolved relatively simple machinery a number of systems for coping with the problem of and ofthe Type I secretion traversing two rather different lipid membranes (the inner processare now beginning proton-impermeable membrane is composed primarily of to be understood. Bacterial phospholipid and proteins while the outer membrane diversity is shown in Type II contains lipopolysaccharide as a major component but systems with alternative relatively few proteins and has channels,called porins, that secondsteps and in the use facilitate entry or exit of small molecules). The SecYEG of other transport systems, translocaseof Escherichiacoli plays avital role in transporting e.g. Type IV systems for proteins into and acrossthe inner membrane. Its eukaryotic export of T-DNA by -tu ?e'l

E 3}*S&$mS**$SYTODAYVOL26/MAY99 Euka ryotic protei n tra nsport dependent translocation acrossthe thylakoid membrane. Proteins, which are destined for secretion, are firstly These pathways all reflect the prokaryotic origins of delivered to and transported acrossthe ER membrane, chloroplasts. Preproteins destined for the ApH-dependent then transported to the Golgi apparatus and thence to pathway have N-terminal signal peptides that differ subtly secretoryvesicles. These vesiclesmove to and fuse with the from classicalsignal peptides by the inclusion of a twin- plasma membrane from whence they are secreted.This arginine motif bordering the hydrophobic region. The processhas to be tightly regulated all the way to control inter Sec-and ApH-dependent pathways seem to be mutually alia protein conformation and, in the caseof hydrolytic exclusive and, remarkably, the latter pathway acts on fully enzymes,prematufe activation. Preproteins can either be folded precursors. The discovery of the second ApH- co-translationally targeted to the ER membrane by SRP, dependent pathway has led to the recognition of the same or post-translationally by the Sec63-dependentroute. In type of pathway in bacteria for the export of folded both casesthe preprotein crossesthe ER membrane via periplasmic proteins requinng cofactors.A fourth pathway, a transmembrane channel, which in both yeast and that may also have a bacterial counterpart, appears to mammalian cells is composedprimarily of three proteins involve the spontaneous insertion of proteins into the (the Sec61complex). The Sec61p of yeast shows homology thylakoid membrane. to the SecY component of the E. co/iSecYEG translocase. Protein transport from the cytosol to peroxisomes is Recent work has revealedthat the transmembrane channel conceptually simpler than chloroplast transport as there is is much wider than that required to accommodate alinearly only a single membrane to cross.\Whilst the vast majority of extruded polypeptide, and thus to the realization that peroxisomal proteins are post-translationally imported substantial folding of the protein may occur whilst it is still from the cytosol (by virtue of short C-terminal targeting being translocated acrossthe membrane. This and other signals), it is becoming increasingly clear that peroxisomal recent advances,such as the revelation that g ting ofthe lipids and some important peroxisomal membrane proteins translocase may be accomplished by transduction of derive from the ER. In her contribution Baker will focus on conformational changes, that occur in the ribosome as the biogenesisofperoxisomes. it translates,will be discussedby Stirling. \Thilst a branch of this general secretorypathway is used Inf lux and eff lux systemsfor small molecules for the delivery of proteins into lysosomes,most proteins For uptake of nutrients the problems are slightly different. of the mitochondria, peroxisomes, chloroplasts and the Often the maior one is that the concentration of a metabolite nucleus arrive at their destination as the result of post- outside the cell is much lower than that in the cell and translational import from the cytoplasm. Proteins uptake has to be against a concentration gradient. One transported from the plant cytosol to the thylakoid lumen solution is to convert the transported solute into a modified of chloroplasts have to traverse three membranes: the form asin the phosphorylation ofsugars by the phospho- outer and inner chloroplast envelope membranes and transferasesystem (PTS). Regulation of sugar rransport at the thylakoid membrane. Chloroplast protein transport the protein level involves inducer exclusion for Gram- is more complicated than origrnally envisaged. Oncd negative bacteria but inducer expulsion in Gram-positive proteins containing chloroplast transit sequenceshave bacteria. Primary and secondary transport systems for been imported into the stroma they may undergo solutes respectively use energy from ATP hydrolysis and SRP-dependent targeting and Sec-dependent or ApH- from ion gradients; they can catalyseboth uptake and efflux. Poolman will review thesesystems with particular emphasis on transport systemsused in adaptation to osmotic srresses. Efflux systemsare used to pump out antibiotics, heavy metals and toxic metabolites (including wasre producrs

IEE-L,rmEN-\ from intermediary metabolism) from cells and thus help rH's wA'Y I / regulate the environment within the cell. Rosen will ,/ QoLqt Tdr5 @A'l I describethe ubiquitous arsenite efflux pumps and the ways in which accessory factors improve the efficacy of the a resistancemechanism. Specific binding of a peripheral membrane ATPase to bacterial pmf-dependent arsenite Er carriersconvert them into primary arsenitepumps, and possessionofan arsenatereductase effectively extendsthe range ofsubstratesthat arsenitetransporrers can extrude. Lewis will describe the multidrug resistancepumps (MDRs) that occur in bacterial,animal and plant cells.By contrast with solute influx transporters, MDRs have

'n HE1NT To BE remarkably broad substratespecificity; amphipathic Ncf SIRE qHA'T t wt+s cations sEEtns so uNcERmtN I UFE) nf DsTlNfrTloN are generally the preferred substrates,even though MDRs

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occupy four different mem- Recurrentthemes brane protein superfamilies. Cells use different signal peptides as sorting codes for A variety of mechanisms delivery via different systems.Bacterial, chloroplast and and pathways for the ligand yeast pfoteins using the Sec-dependent route have the 'classical' are used; these include a signal peptide, whereassignal peptides for the pathway whereby the ligand ApH-dependent route in chloroplasts and bacteria contain is flipped from the inner twin-Arg regions next to the hydrophobic core. These two leaflet to the outer leaflet of systems appear to have evolved to transport unfolded and the membrane and another folded proteins, respectively.In some casesbipartite signal where transport is from the sequencesare used, each to cross one of two successive outer leaflet to the external membranes. The old concept of proteins always being medium using a porin to translocated in the unfolded state is obviously not true. F,*7#y --n"3&'te's tfavefse the outer mem- Sequence comparisons have proven useful in identifying J*-> ffi brane. The polarity of the motifs characteristicof particular proteins, e.g. MDR efflux P.pUae t-o-kes Pdg ligand and its partitioning translocases can be identified by sequence analysis. in the lipid bilayer may Chaperones are important in controlling the folding and determine the route of efflux. Lewis will also discussthe unfolding of proteins. Proteins like SecB and Bip bind possibility that naturally occurring plant alkaloids would unfolded proteins to prevent unwanted hydrophobic be potent antimicrobials if not for the evolution of MDRs. interactions. Some chaperones,as in the Yop system, are As overexpressionof MDRs causesclinically significant specific to particular proteins to ensure delivery in good multidrug resistance,the possibility of combating this shape. You'll neuerwalk alone corld well be the theme tune of resistanceby using the natural MDR inhibitors produced the transport world. by plants (alongside the alkaloids) in combination with Space regrettably precludes further discussion of antimicrobials will alsobe discussed. recurrent themes or of the many applications like antibiotic Sequence comparison studies have been applied to resistance,inherited disease,inhibitor design, etc., that transport proteins and are particularly valuable when stem from the fundamental science. applied to membrane proteins, since so little hfgh- However, the organizers of the Symposium onHow Do resolution structural data exist. Such studies have prbved MoleculesCross Microbial Membranes?hope that this preview useful in grouping proteins into evolutionaiily related. of the programme is sufficient to whet your appetire ro families, identifying conservedmotifs are of functional attend the sessionat Leedsin September. significance, etc. Proteins with six transmembrane Seeyou there and may you arrive safely! segments are found in many transpoft families and seem ' to have evolved independently in several families; the O Dr BruceWardhelped to organizethis symposium preferencefor this configuration is still unknown. Saierwill andcan be contactedat lnstitutefor Celland discuss repeat elements withln pefmeases,the recognition MolecularBiology, University of Edinburgh 'permeases of fused domains and variations in with TeLol 31 6505370;e'mail [email protected] multidomains. Othersym posi u m organizers Roleof lipids O Professor S. Baumberg Lipids play crucial and often undervalued roles in transport DepartmentofBiology, University of Leeds of molecules acrossmembranes. The phospholipid bilayer O ProfessorC.J. Stirling stabilizes the hydrophobic membrane-spanning cr-helices Schoolof BiologicalSciences, U niversity of from which most membrane proteins are constructed. Manchester Phospholipids may interact directly with the hydrophobic O DrJ.K.Broome-Smith signal peptides ofpresecretory proteins. The internal and Schoolof BiologicalSciences, University of Sussex external layersof membrane bilayers may be asymmetric in O Dr P.M.Goodwin their lipid composition and this may play a role in the TheWel lco m e Trust,Lo nd on recognition of sequencesresponsible for correct orientation of integral membrane proteins in membranes. For at least F urtber details of the meetingappear on p, 84 and a bookingform one MDR the membrane influencesthe substratespecificity is onp. 101 . Tbesymposiuru will bepablished as a book.A reuiew of the MDR, by selection only of ligands that partition and orderformwill appearin afature issueof Microbiology Today, in the membrane. For example the mammalian P- glycoprotein works by a flippase mechanism (transporting molecules from the inner to the outer leaflet of the membrane by flipping them over). Lipids also play vital rolesin vesicular transport ofproteins between organelles.

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l:ri,:.ll ,,:al'], ';:.i:.'r. r:::,1::. ::r-Ifi ,,11.:lr Let's have a debate! ai:.i: rj .i..:,llr,iti :,,llri PhilipMortimer ''ii rll.:i. :,it.lt.': r',.t: ': tt:: tli

I To be successful,a scientific meeting must provide that scienceis about factsand not about opinions, but this is ,r \ a mix of data and interpretation that instructs and unconvincing.Ideas, not facts,are what counr. Ifit is agreed , , , . stimulates the audience,and leadsthem to modify that scientific meetings need less undigested fact un4 :.-1-,, their opinions and possibly adapt their research.Sadly, meet- unchallengedassertion, and more discussionand argument, i:,1.,1:r ings often fail by thesecriteria. Instead, keynote speakersjet then a debareis the way to breakrhe mould. Jusr as no into the venue,bearing slides.They deliver a well-honed scientificdata should be taken on rrust until it has been ,-,'. speechto a passiveaudience and they leave the sameday. replicated elsewhere,no scientific proposition should be ,r-,,, Other speakers(who may at least have paid their way) grve accepteduntil it has been aired in public. If a proposition ,1,,,,. talks ofvariable quality. A cargoofoffered papersand posters cannot be defendedin debatethere is probably something :,.r.,, is added to the freight ofscientific data, and the audience wrong with it. Moreover (and this is an important 1.,-,1 begins to reel under the weight of information. Coping consideration),practice in debating will help scientists ,,.' strategiesare adopted, such aslingering in the coffeebar, when, in committees or elsewhere,they are called upon to ,,, .., getting out of bed late or leaving the meetin g early.The next present and explain technical issues,and arguefor funds. ,i,.:,., time, facedwith the prospect of another conferenceof the The subject and the wording of the morion areessential ro ,', : samesort, people consult their bulging diaries and decide the successof a debate.It is said that the defeatof the motion ...,,,,, that they would prefer instead to ha.vethe information that'Tbis Hausetuould figbt for King and Crtrrntry', at rhe filtered through the refereeingprocess ofthe journals. In debating societyof an ancientEnglish universityin 1933 .,;,,.,, particular, vetefans who might have the most to contribute fed Adolf Hitler's ambitions and altered rhe course of ,.,:'.,.., to a meeting and are best placed to discussor challenge from history. It will take more than the ourcome of a debate -_,,.- the floor are the most likely not to find rhe time to artend. to change the course of science,yet adebate can bring a :..,,.,.,,,..: Is it then still possibleto organizea meeting thar, rather somnolent post-prandial sessionto life. It can rurn rhe final ,,.,, r, than being a failed data transplant, is a successfulinter- hours of a meeting from a dispiriting successionof exits by ..:.1:,, action between old and yollng, experienced and naive, an audiencethat hasbeen furtively consulting timetables66 i.,'.,,,, knowledgeable and ignorant? One ploy, which the SGM identify the earlier train, to an arresting clash of argu-e.rts ..4,'.-l Clinical Virology Group has been trying out with some that holds the attention ofall. 1i.,-,, success,is to include a debatein the programme. A topical Nor should the impact on informed opinion of a well ,.:.,1. issueis chosenand four or more main speakersare invited to fought debate on a topical issuebe discounted. The most ...,.. argue a point. This gets people, both seniors and young famous British scientific debate that ever took place was ,..,.,,,.':, turks, on to their feet to set olrt and defend their opinions that betweenBishop Wilberforce (known on accountof his aboutsignificant issues.At the recentmeeting ofthe Society oleaginousmanner asSoapy Sam) and Thomas Huxley. The '..,,.,. -J7arwick, ';'.,.,1,, at we debated universal screening of antenatal issuewas the descentof man and the outcome wasthat man's patients for HIV infection. The proceedings lasted over rwo relationshipto the apescame to be accepted.That o..uslsn ,.,,-., hoursand virtually no-one left the lecture theatre. has not been forgotten after over 100 years,so it should not ....r,1. 'the \Wherethe form of disputation known as debate' be thought that a debatein a current scientificmeeting will ,:,.:..1' originates is unclear, but it is a structured contest in whidh countfor norhing. opposing views about important issues are set out and Attendance at scientific societies,and the SGM is no i.,.,,.r testedin front of a non-partisan audience which then votes exception, is suffering from rhe pressuresthat adminis- ..:.,',t.,. for one side or the other. They do so on the merits of the case trative responsibilities,greater accountability and growing,.,.'1,:.. aspresented by the main speakers.The speakersmay well teaching commitments put on people'stime. Yet societies .:,.,r1,,' seeboth sidesof an argument, and indeed might have been need members' attendanceand their participation u, -..,- , t.,.,'''.. ableto arguethe opposite one, but their role is to advocate ings just asmuch as they need their subscriptions. n6sl6s6 :....1-,;11 onecause and refute the orher. The analogy with English such fellowship a society,however rich ir may be, is mori- :,..,.,r,r andAmerican coluts oflaw is obvious. bund. The debate is an occasionwhere seriousissues can be .,,,..r.;, The exerciseis academic- no-one is bound by the out- thrashed out openly, and in a form where no*one t, t.r*o- l l:'i. f, comeof the motion or by the arguments advanced.A debate, cably committed, or immune by virtue of rheir position ;i '..11.r;1.' like a cricket or football match, is simply a game played to from challenge. It is a place where tenured scientists 62n gs .:.il.ir.,i \ rulesbut it hasa seriouspurpose. It airs and testsargumenrs, called upon to defend their work and opinions, and where . -.....,. it encouragesspeakers and listeners to evaluate their the young and lesssecure can promore theirs. -,,-,.1. opinionsand, becausethere is a time constraint,it forces A final warning to the organizersof scientific gatherings: :,,,,1,: peopleto structure, prioritize and refine rheir arguments. It a debatecould serious/y enliuen your nteeting! ..,r.....'... oftenreveals the weaknessesof a generally held opinion or ..:.i..,...,.. themerits of a minority one.Above all, it is rarelydull. O Dr Philip Mortimer is Convener of theSG M .,r,,l.,:' Debating,an important sedentarysport in British schools ClinicalVirology Group. He can be contacted at t,.t,,,.,, andr"rniversities until more visceral recreationstook over, PHLS Hepatitis and RetrovirusLaboratory, CPHL, haslong beenin decline, and may be unfamiliar to younger 61 Colindale Avenue, London NWg sHT -.,t,r,:., scientists.If so,it is time to revive it. It hasoften beenargued Tel.0181200 44OO;Fax 0181 2OO1569 ,,,.:.-l ffiryffirasffiffiWffiwwwwmsffi ffiw&ffiwffiffi ffiwwffiffiWWwrefuwww ffiww€#wffi Annual General OThe Societynotes with regrettheuntimelydeath of Meeting 1999 Professor Gordon 5.A.B. Stewart, U nive rs i ty of Microbiology Today Nottingham.Professor Stewart had a distinguishedresearch Meeting O Councilplaced on recordits congratulations to allconcerned, TheAnnual General careerand was the Society's1 997 ColworthPrize Lecturer. especiallyJanet H urst, lan Atherton and Janice Meeki ngs, the of the Societywillbe heldon The recentsymposium volume (no. 5Z MicrobialSignalling and productionteam at MarlboroughHouse, on the excellent Tuesday,7 September 1999, Communication),to whichhe contributed,has been dedicated appearance,content and i mpact of thef irst issue of atthe SocietyMeeting atthe to ProfessorStewart's memory. MicrobiologyToday. Universityof Leeds.Agenda papers,including reports OThe Societyalso noies with regretthedeath of fbrms of office fromOfficers and Group Professor P. Novotny (mem ber s ince 1974), An o b ituary Conveners,and the Accounts can be found on the web at http://wvrrwbc.ic.ac.uk/research/ OThe Presidentoutlined some concerns he hadregarding the of the Societyfor 1998 will fairweather/obit-novotny. html lengthyterms of office of seniorOff icers of the Societywhich be circulatedwith the August werepossibly a seriousdeterrentto able candidates who might issue of Mi crobi ology Today. takeon these important posts. Council may decide to bringa resolution to the nextAG M coverin g thisissue, and comments SGMSymposium fromordinary members of the Societywould be welcome. Volumes Gontasts Thecontrrbutions tothe April1999 symposium on O Difficultiessometimes arise in filling not only Officer Mi crobi al Sign al I i ng and vacancies,but also on occasionthose of ordinarymembership Comm u n ication are available of Council,and in attracting high quality candidates forthe asVolume 57 in the series, A Society'sprize lecturesh ips, Mem bers ag reed that a valuable reviewof the book appears on toolfor trawlingdepartments would be a comprehensive, p.66.Asusual,there isa60 % up-to-datelist of seniorcontact persons in relevant discounttomembers buying departmentsin universities,institutes and industry.Anyone theirpersonal copies, The whocould fulfil such a roleln their department is asked to oricesare as follows: contactJanet Hurst at SGM Headquarlers. Memberc lnvestment policy s26,00/$46,00 OThe efficienthandling of itscapital investments is vitalto the Non.members 15.00 futurefinancial security of the Society.Due to changesin the s65.00/$1 organizationof DresdnerRCM GlobalInvestors, our investment StudentMembers managers,Council instructed the Treasurer, Finance Manager s16,00 andExecutive Secretaryto make athorough review of beordered by investmentpolicy and the optionsfor f undmanagement. With Thebook can inthis guidancefrom our auditors and after extensive discussion by postusing the form Microbiol ogy Tod ay. theTreasurer's committee, Council agreed to transferthe rssueof to porlfolio to MercuryAsset Management for tnvestment in large, Thisform can also be used pastvolumesinprint commonmanaged f undsfor charities,lronically, in their lastyear orderany atthe time of managingthe Society'sindependent fund, the Dresdnerteam thatyoumissed haveperformed very well on ourbehalf and the Society'sassets publication, haveincreased signif icantly in notionalvalue. StudentMembers wishing topurchase Symposium Public understanding of science Volumesat the d iscounted rateshould write to the Grants OWiththe appointmentof our EducationOfficer, a number Officeat Marlborough House of newinitiatives are coming forward and Councilwas pleased fora soecral order form, to approvea proposaltoextend the useof the Society's Developmentsin Teaching Fund to includeaspects of public understandingof science,For details of proceduresfor aoplicationforfunds see p.B 1, Wanted prizes GilDomingue, University Small in universitY of Exeter,is trying to find a departments FixedHead 10 x 100ml O Councilalso supported enthusiastically a proposalto f und centrifuge head suitable smallprizes in universitydepartments for undergraduateswith foranMSEAutomatic highlevels of attainmentin microbiology.Details will be Superspeed50.lf you announcedin afuture issueof MicrobiologyToday' canhelp, please contact Gilor Frieda Jorgensen at & Charles Penn, General SecretarY ThePHLS FMRU, Church Lane,Exeter EX2 sAD (Tel.01392 402955; Fax 01392 41 2835;e-mail g,dom i ng ue@ exete r.ac.u k)

Eil ffi Xffiffi#ffi*#fu#ffiY|ODAYVOL26/MAY99 Grants ffi#ax**'&$epwx(b) Examplesof projects understandingof .JiLpl...i iti: ti l;',:rr.1lri:*r: ;:l 1i .t$*$m'*r*mm$p,m whichmight be funded microbiology.These might Yt'r*r Applicationforms are ffiww*$m,p*"wmmtincludethe provisionof includetalks, workshops, ffiqlF{$$s:$r*,,*m# * 't availablef rom the Grants "" o teachingmaterials (e.g. demonstrations, posters, , "'" Office at SGM HO or may videos,slides, posters), the leaflets, broadcasts, activities Memberswho are bedownloaded from the developmentof reliable, at sciencefestivals and permanentlyresident in a Awardsfor PUS web site, novelpractical exercises, audio-visualor computer- developingcountry are proiects now available reminded new approachesto teaching/ basedpackages. These Pleasestate clearly whether a thattheymay apply for Onlyasmallnumber learningfamiliar concepts activitiescan take placeas formis required for ateaching f undingto acquirefor their of applicationsto the (e.g.computer si mulations nario{aSFTeventatthe aidor a PUS award. librariesbooks, or possibly journals, Developmentsin Teachi ng or tutorials)or anyother applicant'splace of work but relatingto The nlncinn Aalalar Fundhave been received in appropriateaspect, lt is not PUS activitiesthat are part of microbiology. These an n ual applicationsis29 October recentyears. This is probably intendedthat the Fund theprogramme of anopen awardsare available as a 1999. dueto thechanging nature of shouldsubsidrze normal dayto promoteihe institution resultof a generousdonation microbiologyteaching at all departmentalteaching areineligible forfunding. f rom Professorl Watanabe levelsand constraints such practices;the Societywishes of Japan.Fulldetails of the (b)Applicants must provide asthe diminishing time that to encouragein novation. a schemewere published on detaileddescription academicstaff haveto of the p.24 of the Februaryissue of (c)Successful applicants proposed S*$*tS'$'r,ig" devisenovel applications. initiative,which it is M ic rob i ology Today.fhe willbe notified in Februaryto anticipatedwilltake place Inrecognition of this in ':^ closingdate forthe receipt facilitateforward planning for 2000,f ullcostings and "!", situationand infurtherance " . r- r- .. ^. r .--.:..-: of applications,which should theirproject. They will normally evidence : of Societypolicyto promote of anycollaborations be madeto the GrantsOffice be requiredto makethe or othersponsorship. thepublic understanding of Each 1999Awads at SGM Headquarters,is resultsof theirwork available application microbiologicalissues, shouldalso include 4 October1999. to Societymembers, within a safetyrisk assessment Onlyfour applications were Councilhas decided thatthe and 1Bmonths of theaward being evidenceof, receivedand the AwardPanel remitof thefund should be or costingfor, made.This will include a appropriatepublic agreedthatthe followingtwo changed.From now on liability presentationat a Society insurance projectsshould be f unded: memberswill be able to apply coverif the activity meetingand publicationof an isto be held public '.f;.ri!i, Non-SGM forsmall g rantsfor relevant ata venue. r{lr i;i, CAL Unit,School article in Microbiology Today. Payments sciencepromotion initiatrves to helperssuch as of Health,University of Wales award Physicalmaterials, whether undergraduateswho aswell as for f undingto are Swansea:to developa case- ,^.....) offprints, videos, slides, givingup theirf ree . support developments likely timeto basedexploration of cltnical computerprograms, microbial deliverthe to leadto an improvementin activitymay be microbiology(S2,92 1,70). strainsor inother forms, includedin the costings. theteaching of anyaspect "{i*{:*qs,{t!.t shouldbe readilyavailable to iiil',i''.;, *,:,r,rtn,School of microbiologyrelevant to Applicantsshould also $il$*s-t't,*r*x$ Societymembers on free or of BiologicalSciences, secondaryortertiary indicatehow they will assess low-costloan or purchasefor University of WalesSwansea: (includingpostgraduate) the successof theirevent, a periodof at leastfive years to runpracticalworkshops on 'Y,r$,s:*'t educationin the UK.Funding afterterminationof the project. (c)Successf microbiologyinprimary fortoursto overseashigher ulappl icants willbe notifiedin Januaryto schools(S765), Thesefellowships help educationinstitutions to (d)The Society would facilitatetheir arrangements. womenreturn to their studymethods of teaching encourage com mercial or Pastawards A reportof the activitymust scientific careers after taking largeclasses will no longer otherdisseminationof the ' be submittedto the Society The reporlshave now a breakforfamily reasons. beavailable. resrrlts of ihe'"- nroiectto g "' Y' within3 monthsof the beenreceived for several Thefellowships are normally widerpublic. All Intellectual Applicationsf rom members completionof the project, completedprojects. These for two years,worth over PropertyRights, including arenow invited for either Thisshould take the form of includeDr SarahWatkinson's S I 2000,flexible as the, copyrightand design rights, categoryof award.The f ull anarticle for publication in accountof hertripto theUSA arepart-time, tenable at a inany materials produced as rulesof the schemeare the'GoingPublic' section whereshe learnt aboutthe universityor an industrial a resultof thegrant will be givenbelow. usesof theweb forteaching laboratorydesigned rraclor] in tha Qnniafir oI M icro bi ol ogy Today, A for copyof the resultsof the largeclasses and some novel retrainingand new research ffiq*{$*; (2 ^.^^+i^^l ^,,^-^i-^^ i^ 3. PUSawards assessmentexercise Pr aLLrLdr u Ut LtSe) lt I and restrictedto science, 1,Applicants must be simplequestionnaire or microbialgenetics; Dr Mark engi neeri ng and technology. (a)Applicants may seek membersof the Society, summaryof publiccomments Roberts'insightsinto the uses f undingof no morethan Applicantsmust have afirst currentlyresiding in the UK onthe event will suff ice) to whjch computer-assisted S 1,000 for smallprojects degree,have taken a break orRepublic of lreland. shouldalso be provided. learningis put in Australiafor to promotethe public forthreeyears and be teachingveterinary 2. Practicalteachi ng aids residentin the U K.Conracr: bacteriologyand mycology; Jennifer Woolley, The Daphne (a)Applicantsmay seek anddetails of the Biodiversity JacksonTrust, Deparlment of support,normally with in the Consortium Untt's'Microbial Physics,University of Surrey, rangeS200-S3,500, for: FieldTrip'CD-ROM GuildfordGU2 5XH (e-mail developedby Professor (i)purchase of consumable [email protected]), Johanna Laybourn-Parry and materials,but not capital hercolleag ues. Shortened equipment; versionsnf ihese rennr[5yyill (ii)short-term assistance, appearin Mic robiology Today e.g.vacation employment indue course. ofanundergraduate, or exceptionallya post- graduateafter expiry of a studentship.

i',i'f${l$t{}{*t .3$"*#Y TODAY VO L 26l MAY99f ffim&mwwxm&ffiwmmffi lohn Redwood ffimww&wpmwm& MPvis'lts ffiwmd Marlborcugh Councilaims to assist House microbiologistsindeveloPing It isCouncil policyto promote countriesand Eastern EuroPe understandingand knowledge throughthe International of microbiologicalissues on DevelopmentFund. Awards the wideststage. This aremade by competition, includessubmitting evidence Sax*,p*sm to Parliamentaryinquiries and GovernmentDepartment 1, Supportvisits (travel and consultations,and mai ntai ning accommodation)bymembers contactswith politicianson a ofthe SGM to laboratoriesin non-partypartisan basis. countrieswhere microbiologY isi nadequately develoPed MadboroughHouse,the butwhere its f urther Society'sHeadquarters, developmentmay assist liesintheWokingham educationorthe economy of parliamentaryconstituency of the Rt.Hon.John Redwood thesecountries, The PUrPose ofthe visits must be to give MBwho isShadow Minister lecturecourses and forTradeand Industry, shorl ES\RIAOINO fYTNINO POSI laboratorytraining in subjects As such,he hasoverall designedto meettheneeds ffia*$dm$6au*s responsrbilitvfor scienceand ffiwrcffimffi tr ffi Wffimkwww Wwxs*d technologyibsues within the ofthese countries. The 1. Applicationsforsums countriesmay vary from time- wffiffiwdffiffiffiffi ShadowCabinet, and speaks betweenS1,000 and $5,000 on theseissues forthe to-timebut at presentthese SeminarSpeakers Fund is to promote willbe considered first. No The purposeof the ConservativeOpposition in includemany places in the indepartmental seminar applications above SZ0O0 talkson microbiologicaltopics Parliament.lt wastherefore FarEast, Af rica, South and .^,1il t-^ ^^^^^+^,] areinvited from highereducation vvlll uu duusPLeu' programmes.Applications appropriatethat he was able CentralAmerica, the Indian institutionswhere microbiology is taughtfor grants of upto 2, Applicantsmust be to visitMarlborough House sub-continent and Eastern S2OOtowards the travel,and if necessaryaccommodation, of the Society. on 12 March,tolearn about andCentral Europe, Host members invitedspeaker. Applications will be dealtwith expensesof an the rangeof SGM's activities, laboratoriesare usual lY basisduring the academicyear. 3. Inmaking applications on afirsi come,first served meetthestaff and discuss expectedto providesome shouldbe sentto the GrantsOff ice at for supportfor givingshort Writtensubmissions mattersof scienceand evidenceof localsupport for lecturecourses or laboratory SGM Headquartersfor consideration,The rulesof the scheme thecourses. educationpolicywith trarning,detailed information aredetailed below reoresentativesof Counctt mustbe providedaboutthe 2. Allowpurchase of basic 1. The schemeis open to highereducation institutions in and seniorstaff, Matters relevanceand qualityofthe equipmentessential for the the U K and Republicof lrelandwhere microbiology is taught' coveredincluded the trainingcourse and the needsof such training Normallyonly one department within an institutionwill be importanceof supportfor degreeof localsupport for courses. eligiblefor an awardwithin each academic year, which is basic research,the effects course, 3. ProvideSociety journals, t delinedas runningfrom September1 999 to June 2000, lt is of excessivemonitoring and symposiaand special 4. Eachapplication must expectedthat departments will collaborate in selecting a centralization,em ployment publicationsto established beaccompanied byfull semlnars0eaKer. conditionsfor academicand documents researchmicrobiologists, librariesfor a limitedperiod of supporting wtllonlybe acceptedfrom departments,not 2. Applications includingiheir abilityto exploit timeat reduced or zero cost, Societies. 5, Aconditionof funding f romStudent Microbiology findingscommercially, and especiallywhenitcan be (exceptfor provisionof 3. Up to two speakersmay be funded each year, provided the the roleof the scientifrc shownthat these publications publications)is that a brief totalaward to the institutiondoes not normallyexceed 5200. communrtyin giving advice arenot currently reasonablY rann# crrilohla {ar I vHv, $ andpromoting public availableinthe country MicrobiologyToday,be 4. Seminarsmust be advertisedregionally as sponsoredbythe concerneo, understanding of contentious provided, Society, issuessuch as G M food 4, Supportnational Applicationsto the Fundare 5. Awardswill be paidretrospectively on receiptof evidenceof and BSE, microbiologicalfacilities, e.g. now invited,Four copies, the actualexpenses incurred. (which Themicrobiological highlight culture collections includingfull suppofting underpinmicrobiology), 6. Applicationsshould contain the followinginformation. of aworkinglunch was documents,should be sentto providedby three excellent wheretheserun into (a) namesand addresses of the speaker(s)to be invited the International SecretarY, The cheesesproduced by local temporary diff iculties. (Professor of the talk(s), J,W Almond, andthe topic cneesemaKers. PasteurM6rieux Connaught, 5, Supportany other small '1541 (b) Evidence,in the form of a programme,that an active AvenueMarcel The photographabove projecttoassist in technologY semlnarprogramme is already established in the Marcy shows(from leftto right) transferf rom Western Eu rope M6rieux,69280 Whereno previousprogramme exists, good department(s). HowardDalton (SGM tothe areas mentioned above llEtoile,France), givenforthe request,such as the reasonshould be President),Don Ritchie(SG M forwhich other sources of newdepartment. The closingdate for establishmentof a ProfessronalAffai rs Off icer), fundingdo not exist. This applicationsis 1 October (c) Detailsof anysponsorship for seminarsthatthe department John RedwoodMP, Ron mightinclude provision of 1999. equipmenttoa nominated alreadyhas (or isanticipating). Fraser(SGMExecutive Secretary)and Janet Hurst centreatwhich a memberis (d) audience for the seminar, wh ich An indication of the target (SGM DeputyExecutive workingpermanently. ndergrad uates and postgrad uates. may incl ude u Secretary).

E nn**K$ffi X#hffiffiY TODAYVOL26IMAY99 ffi'cp'wmwffp$s:r'w$l,$wssffiml ffi,ffiffi $mm'qp&p$m$qmffig3g' Prize Lecturesand Awalds

-'--... New 4.Therecipientof the Malory StephensonPrize pfOcedUfe fOf TheFleming Lecture is awarded annuallyforoutstanding *!utt*rrx $.t E*,{t jgf rs $t Lectureshipwill be expected nominations researchin any branch of microbiologyby ayoung St*'$xg,r &,,$:l$ti!.$i:'tjl to givea lecturebased on microbiologistin the earlystages of his/hercareer. The the workfor whichthe Prize ln recentyearsCouncil has awardisS1,000. Lectureshiphas been beendisappointed bythe lack awardedto a meetingof the 1, Nomineesshould normally have been engaged in Thef irstcall for nominatlons of nominationsforthe range Society,normally the Spri ng researchfor not morethan 10 yearsafter doctoral qualif ication waspublished in the February of prestigiousawards made meetingfollowing the or equivalent.Years may be addedto thistotal in respectof issue of Microbiology Today bytheSociety in recognition announcement of the award. careerbreaks, for parenthoodor othersubstantive reasons. (Vo|.26,p.23). Please note of distinguishedcontributions Therecipient will be strongly thattheclosing date for to microbiology.lthas 2.There should normally have been a connectionwith the encouragedto publishthe nominationshas been thereforebeen decided to scientificactivity of the Society,either by meansof pastand lecturein either Microbiology changedto fit inwith the publishannually in the May continuingmembership of theSociety (a minimumof 3 years' or the Journalof General new procedure. issue of M icrobiology Today membership of the Societywou ld normallybe expected),or Virology,whichever is the the rulesfor eachprize lecture pastpresentation(s) at a Societymeeting or publication(s)in Rules moresuitable. The choice will dueto be awardedin the a Societyjournal, or anorganizational oradministrative be at the discretionof the 1. The MarloryStephenson followingyear, lt is hoped contributionto the scientificwork of the Societr, Editorsof thejournals. thatthis new system will PrrzeLecture shall be 3. Candidates,who neednot be membersof the Societv, assistmembers in making awardedbiennially for an shouldsubmit an outline CV including details of qualifications, nominations.Theaward outstandingcontribution of 1 scholarships,research grants obtained, etc., a lisiof panelwill consider the currentimportance in publications,an outline of theircareerprogression (posts held nominationsin the autumn microbiology,without L*iI,{,:{s*frY*f' in postdoctoralresearch) and the namesof two memberswho restrrction andtheir recommendations on the areaof {,}S{;}r aref amiliarwith their work, who willbe askedto providea microbiologyin which the t willbe takento November statementdetailing the candidate'scontribution to awardis made, The 1999 FlemingLecture Councilfor approval,The microbiologyand meritfor the award.Alternatively, mem bers hasbeen awarded to outcomewill be announced 2.Nominations forthe whowish to makea nominationshould provide such a Dr DavidRichardson, School inthe Februaryrssue of MarloryStephenson Prize statementand shou ld arrange for a secondmember wrlling of BiologicalSciences, MicrobiologyToday. Lectureshall be madeby any to supportthe nominationto providea statement,and should Universityof EastAngiia,in two membersof the Society; Nominationsare now sought askthe candidateto providethe CVand publicationslist, recognitionof hiscontributron nominee forthe prizelectures listed on TheGeneral Secretarywill be pleasedto advisemembers the neednot be a mamhornf *ho Qnnial,, to theunderstanding of thispage.A nomination form preparingnominations about the information to besupplied. f undamentalphysiolog ical Nominationsshould be maybe downloadedfrom the and molecularaspects of 4.The recipientwill be expected to givea lecturebased on his accompaniedby a statement SGM web siteor obtained bacterialrespiration. The iitle or herworktoa meetinqof theSociety, which will usually not be of thecontribution to fromthe ExecutiveSecretary of hislecture, which will be thatwhich takes placein the spring,He or she maybe aikeOUy microbiologymade by the at SocietyHO. Please deliveredat the Society theCouncil of theSocietvtorepeatthe lecture at another nominee,supported by compleiethe form andsend it meetingat the University of centrein this country or in Euro'pe.Expenses of the lecturer reprintsor other appropriate to DrCharlesPenn, Schoolof I oodq in Scntomhar l OOO ic willbe paidby the Society.Requests for sucha secondlecture documentation,A brief BiologicalScience, University Bacterial respi ration: a shouldbe madeto the GeneralSecretary and will be curriculum vitaeof the of Birmingham,Birmingham flevihle nrnra

: occasion. : .1.': The lectureis awarded every otheryear by SG M on behalf of the Instituteof Biologyfor an outstanding contribution to researchin a moreapplilO areaof microbiology,or inan area wheremicrobiology impinges on other areas of biology,and wherethe topicwould be attractiveto a widerbiological arrdienceThe nrize is 9.500. Contact Charles Penn for f urtherdetails. &mmffiw.mffiffi %ffiffiffi Meetings on 144th Ordinary Meeting ffi S S*ptemh*r the web UniversityofLeeds fuiX*i**r"r Isr Ma*h ir"l ** : h4*: b ile Fr*t* in S*m $ lex*s 7-lOSeptember in hdi*r*-nrgnni*ms Uo-to-date i nformation Detailsofmany ofthe symposia were published inthe February issue of Physiology,Biochemistry &Molecular Genetics Group on futureSociety (liz Microbiologyloday(pp28-29),See web site f0rfull information aboutthe 0rganizer:LizSockett sockett@nottingham ac.uk) meetingsis available on prizewinner pr0grammechanges asthey occur and to download abooking form ifyou Aspeaker inthis session isthe Nobel J Walker,Iitlesand the web site http://www. papers posters donotwish touse the one on p.99 ofthis magazine, abstractsforoffered and shouldbesent to the organizer socgenmicrobiol.org,uk by1 June 1$99 Meetingg & fu4min$ynrp*siurn {7*S S*pt*mb*ri H*w ffichX*i**ul** {)r*n* hdiE:r*bialfvlmrnhr*ns*? W S*1 i) $cpten"rb*r organization t)*ep $ ubsn"*r'fa** ffiimsph*r* Thissymposium willbe published inbook form See p, 74 for a preview ofthe jointly Theprogrammes of topicstobe covered. EnvironmentalMicrobiology Group withthe the Society'smeetings GeologicalSociety Marine Studies Group bythe 0rganizer:J,Parkes (j.parkes@bristol,ac uk) areorganized O OTHER SYM POSIA committeesof the Iitlesand ab$racts foroffered papers andposters (young scienti$s S ? $*pt*mb*r specialinterest g roups, particularlywelcome) should besent to the organizer by1 June 19$$ T*n*hin g Mi*r*i:i*l*gy t* N*n-rni*r*bi*i*gr*tx : co-ordinatedbythe tl:e thallcng* *{ hd*d*larStrx*tur*x ScientificMeetings O SPECIAL EVENTSFOR YOU NG ER M EM BERS EducationGroup Officer,Dr PatGoodwin, 0rganizer:Helen0'Sullivan (osullih@livhope,ac,uk) & ? S*pt*nrL:*r Suggestionsfor topicsfor Fr-ornegaPriae Final futuresymposia are W 7*S S*pt*mb*r Promegasponsors thiscompetition toencourage excellence inscientific alwayswelcome. See young judged fi *il Lysi*in Ferm*nta{i*n *nejffi i* g:rccessing communicationby scientists,Group Committees havenow the o,95 for contactdetails oralor poster presentations bymembers under 2B related torecent Group Fermentation&Bioprocessing Group of GrouoConveners. symposiaThefinalists goforward tocompete forPromega Prizes ina special SponsoredbyNew Brunswick Scientific (UK) Ltd Administrationof sessionofshort oral presentations ontheir research atLeeds There are two 0rganizer:RobCumming meetingsis carried out prizesof1200 each tobe won and the winners willgo on to compete forthe Titlesand ab$racts foroffered papers orposters should besent t0 byMrs Josiane Dunn of IilleolYoung Life Scientistof theYr,arin1l}}again$finali$s fromother RegFngland (r.england@uclan,ac,uk)by 1June 1999. the MeetingsOffice at learnedsocieties SGM Headquarters, Y*ung*r {\,4embcrs' ffi***pti*n MarlboroughHouse, S S*1 * Sept*mb*r F**d-b*rn* infc*ti*n* *r:d $nt*xis:ati*** Inthe evening following thecompetition therewill be a special event for BasingstokeRoad, youngermembers - po$grads andpostdocs, Ashort presentation onCVs Microbiallnfection/SystematicJa Evolution/ SpencersWood, andInterviews willbe followed bya wine reception andfinger buffet For a Physiology,Biochemistry &Molecular Genetics Groups ReadingRG7 1AE successfulcareer inmicrobiology it isnecessary tobe as skilled inpromoting jointlywith The Pathological Society Tel.0118 9881805 yourselfascommunicating yourresearch findings - this session willprovide 0rganizers:lanPoxton, Simon Fo$er, Adrian Eley and Niall Logan Fax01 1I 988 5656 invaluableadvice, The event isfree, but entry will be by ticket only which mu$ Titlesand abstracts foroffered papers and po$ers should besentto lan Poxton e-mailmeetings@ bebooked when registering forthe meeting ContactJane Westwellat (i.r,poxton@ed,ac.uk)by1 June 1999. socgenmicrobiol.org.uk MarlboroughHousefor details.

& # $cpt*mh*r Abstracts O OFFEREDPOSTER PAPERS Aeih**iv*Str*r:tur** book Offeredpo$er papers are invited onany aspect ofmicrobiology,Iitles and Cells&CellSurfaces Group (includingfulladdresses) should besent to the Meetings 0ffice at EdinburghMeeting authors 0rganizers:AnthonySmith(prsaws@bath acuk)and Mike Wilson toarrive no later than 1June 1$99. This date isearlier than April1999 MarlboroughHouse, (mwilson @eastmand.ucl.ac,u k) thatpreviously advertised lf possible ab$racts should also be submitted atthis Thef ulltext of the Titlesand ab$racts foroffered papers and posters should besent to the stage;these should arrive n0 latsr lhan 30 June 1999 and be sent by e-mail for abstractsbook is now organizersby1 June 1999. This isan ideal opportunity forresearchers inthe publicationinthe ab$racts book. Amaximum of200 words ispermitted availableas a PDFfile $ructuraland functional aspects ofmicrobial adhesion topresent their work, onthe SG M web site. Postersarewelcome; there are currently twoslots free for oral presentations,

E ffins&g,xrw ilWww&$mgm wtNTER 1999/2000 SPRING 2OOO treatment(FBP Group &SfAM)/ SPRING 2OOI | 45th Ordinary Millennium Meeting Proteases,proteolysls andcontrol 148th Ordinary Meeting 10-14April2000 (PBMG&CCS Groups. 0rganizers: Meeting 5-7 January2000 UniversityofWarwick C,Stirling colin stirling@ man.ac uk 24-30 March -U2001 Universityof Surrey, (jointlywith Societyfor &D, Hodgson [email protected] warwick. Heri ot-Watt n ive rsity ac,uk)/ Public education insafe food Guildford AppliedMicrobiology) & l\tlain$ymp**ium andwater(Ed, Group0 SfAM OVirusInfectran * # MainSynrp**iuni N*wf;hallcngc*to 0rganizer:R,Bishop rh.bishop@ul$ Lifeor ffi*ath*f affell FightingInfe*ticn in tl'rs l-'le#th: th* Threatcf ac.uk)/ Transcriptional controlcircuits *1mt**ntury Viru*Infe*tietn Virusand Clinical Virology Groups infungi(PBMG Group 0rganizer: 0rganizer:GeoffSmith 0rganizers:PGoodwin PAndrew, A,Brown al,brown@abdn. acuk)/ Tole putlished (glsmith@molbiol,ox,ac,uk) G.Smith, DStewart-Tull, M Ea$er Vaccinedelivery (MlGroup, 0rganizer: 0rganizer:GeoffSmith (Cambridge) 0ay1:A, Wyllie andP0yston P0y$on poy$on@ hotmailcom)/ (glsmith@molbiol,oxac.uk) Overviewofapoptosis / D,McCance Pre$igiousspeakers from around Virusentry and exit (V Group (Roche$er, USA)HPV / L Wileman theworld including aUK government 0rganizer:GSmith glsmith@ (Pirbright) ASFV/ HThomas representativeandspokesmen from molbiol,ox.acuk) (St Mary'sLondon) HBV/ WH0,will cover the following topics: Also:Evening workshops, social ffimXwk (USA) AGreenberg CIL and Lessonsfromthe successes and eventsandtrade exhibition papers global ffirmmGh apoptosis/ 0ffered oral failuresof vaccine Furtherdetails ofallsymposia are (Birmingham) programtnesglobalthreat Gommercialization [ay2: P Gallimore / Ihe of availableonthe SGM web site and will of Microbial Adenovirustransformation/ W.Wold emerging infectious diseases / The bepublished inthe next issue of (St Biotechnology LoulsUSA)Adenotlirus apoptosis / worldwide epidemic ofantibiotic- Mic ro bi o Io gy I o d ay.Wher en 0 n am es (Birmingham) 16-17 L,Young EBVi resistantbacteria / Protecting farm ofsymposia organizers aregiven September1 999 (Chester Universityof C,Boshoff BeattyLondon) animalsfrominfectious disease / above,please contact theappropriate Ulsterat (Erlangen, Coleraine HHV-B/ B Fleckenstein Canmoleculartechnioues havearole GroupConvener forinformation (see papers Germany)HVS/ 0ffered oral inthe nrevention ofcontamination of p 95foraddreses) ForJurtherinformation andto offer [ay3 (am): PFreisen (Madison, USA) processedfoodby pathogens? / New papersand po$ers contact Nigel Baculovirus/ C.Bangham (StMary's approachestopublic education inthe iernan(ng.ternan@ul$,ac uk), London)HILV-1 / J Fazackerley preventionofcommunicable disease/ AUTUMN 2OOO Seealso the SGM web site (Edinburgh)Alphaviruses / H-J, Ihiel lsglobal clean water attainable? / The l47th Ordinary (Giessen)BVDV useof microassays inunderstanding Meeting Recent Advances in Titlesand ab$racts f0roffered papers infectionsandin diagnosis / Live 12-15 September2000 Molecular Microbial oroosters should besent tothe attenuatedvectors / The promise Universityof Exeter r Ecology organizerby21 September I gg9,All ofDNA vaccination / Vaccine S tVlain$ympesium 7-8April2000 submissionsshouldcontain the development/ lmmunotherapy of C*rxmunity $tructure UniversityCollege, namesofall authors their affiliations, infectiouscancers / Vaccine and to-op*ration in Galway thetitleofthe paper, the name ofthe productioninplants / Iherapeutic ffir*films zuthorwhowillmake the nresentation antibodiesagainst endotoxaemia and lo te patlished andwhetherthey areeligible for sepsis/ New $rategies foridentifying Titlet.b.a. 0rganizer:Hilary Lappin-Scott 'Autumn considerationfora Promega Prize anddeveloping newantimicrobial 2000 (h,m,[email protected],uk) (seep,89)togetherwith anabstract drugs/ Are molecular methods the NationalUniversity of tmaxllllumtcu\,V0r0s) optimumrouteto antimicrobial Othersymposia: Applications of lreland,Maynooth [ttetlin0Workshops drugs?/ Prospects fora new and recombinanttechnology toindustrial hfluenzaVirus arediscovered formoftherapy: fermentations/ Biofilms ininfection Fordetails of lrish 0rganizer:JohnMcCauley probioticsandphage anddisease / Control ofbiofilms / Branchactivities (john,[email protected]) Mathematicalskillsand Tote published contacttheConvener, [xotbViruses microbiolooists ()thersymposia: Microbial ecology MartinCollins 0rganizer:SusanJacobs offood-poisoning micro-organisms (m.colIi n s@q u b.ac. u k) (jacobs_susan@hotmailcom) (EMGroup &SfAM. 0rganizer: Anyonewishing toparticipate in LindaLawton [email protected],uk) / workshopsshould contact the Molecularepidemiology: sub-specific organizernolatsr than classificationandidentification 1g9g, (SE& CV Groups) / Potable water Sciencejournalist &wwkmwffi$wWW ffi ffiffi&ffiffiK Wffi trffi fu $w$wggw MerielJones takes G.M.Tavlot M. Goval, A.J. Legge, R'J. Shaw & D.Young a lookat some developedfor hospitals oftests,the authors could incurrent Tuberculosisisone of the papers ancientscourges of to identifysub-groups of seethat M,tu bercu los is issuesof the humanity.lt is stillafeared thecausal bacterium DNAfrombonesof one Society'sjournals disease,although it isnow Myco bacte ri u m tube rc u I o s i s youngman had subtle whichhighlight rarein the U K andusually andto checkantibiotic differencesf rom bacterial newand exciting treatablewith anti biotics, sensitivity.DNA is a DNAin another man's persistent bones,This holds outthe in Althoughthe most familiar remarkably developments symptomsof TB are moleculeand a collaboration prospectof tracking microbiological damagetothelungs, in a of medicalscientists and individualstrainsof research, smallnumberofcases it archaeologists have now thedisease through attacksbones,This reportedtheir analyses of long-deadcommunities producesvery characteristic DNAfrombones inthe andtaki ng archaeolog ical scarsthat last as long as graveyardof theAbbey of epidemiologyto anexciting thebones. This enduring St MaryG races. This central newlevel, Londoncemeterywas damagehas been used to I Genotypic analysis of studythe historical spread foundedin 1350 anduseo My cobacteri um t u berc u I osis frcm ofTB bothamong human untilthe dissolution of medieval human remains. communitiesand between themonasteries by King MicrobiologyI45, 899-904. peopleand their domestic HenryVlllin153B,The animals.Indeed, one researchersfound M. hypothesisfor the origin of tuberculosisDNA in bones &Wm*m$fuw.wmk thehuman disease is that bearingTB scarsand not in N.Lea. J.M. Lord & L.M.Roberts about1 5,000 years ago one boneslacking these signs, strainspread from newly indicatingthatthe DNA Theinfamou s Escherichia coliOl57 hasmade a placefor domesticatedcattle and hadnot become scattered itselfas the cause of a particularlylethalform of food goatsto people. duringthe centuries,A poisoning,Researchers atthe Universityof Wanruick have quickcheck for evidence beentrying to understandhow one of itstoxins works. This arenow hoping Scientists of resistancetomodern toxin,called SLT-1 ,is a proteinreleased bythe bacteriathat getclearer information to hospitalanti biotics showed clingsto the surface of gutcells and then enters them. Once originand spread aboutthe that,as antici pated, these inside,one of the normal constituents of the cell makes the TBthroughapplying of oldbacteriawould have fatalmistake of cuttingthe toxin, This lethalf ragmentthen biological molecular beensensitive.After rnterfereswith normal protein production within the cell and Thesehave been methods. workingthrough a series theresult is death, Therehas been a scientific argument about the importance ofthis f ragmentation.Some scientists have detected toxic activitybefore cleavage, although the levelcertainly increasedafterwards, Others, including members of the Warwickgroup, have made changes to the toxin that should haveprevented it beingcut, and then recorded no decrease intoxicity. This has led to speculationthat SLT- 1 canbe snippedin morethan one place, MichaelLord and his colleagues have now reported what happenedwhen they worked through the toxin systematicallyremovin g everypossi ble cleavage site' They thentested these novelversions of toxinfor bothcleavage bycell enzymes and toxicity to mammaliancells. The outcomewas quite clear, The toxin indeed had two possible cleavagesites, Once these were both removed, the cells couldno longer cutthetoxin.Although this intactversion of SLT-1could cause some damage,the cleavableversions werevery much more toxic.

I Proteolytic cleavageof the A subunit is essential for maximum cytotoxicity of Es c heric h ia coI i OItT : H7 Shiga-like toxin- 1. Microbio logy 145, 999 -1004.

VOL26/MAY99 ffiffmwwfuwwffmwww &ffimw dwwp kffiwwffiwffi Microbiologistsare gradually meeting the bacteriathat live deepunderthe sea, In the April 1 999 issueof the IJSB, threenew species of bacteriaand archaeaf rom the sea bed anda newmethod for identifyingone specific group were described.There is increasing interest from scientists worldwidein the biology, chemistry and geology of deep-sea environments,where we canlearn more about the formation h ofthe continents and the incredible diversity of life, An internationalgroup(Marteinsson etal) hasfound one soeciesthat likes its seawater at 4OO times normal ffiatmosphericpressure attemperatures of upto98 "Cllt camefrom samples taken from a hydrothermalvent at a depthof 3550 m inthe Mid-Atlantic Ridge by the submersibleAlvinin 1 993, Boiling water and rock fragmentserupt here f romthe seabed. Once atthe surface, Perhapsinspired bythe difficulties of identifyingorganisms THISPAGEr thesamples were kept oxygen-free in pressurized syringes fromthe extreme environments mentioned above, in their Theunmanned submersible (alka usedfor collection ofsamples ina hotoven, Repeated dilution left the scientists with one secondpaper in the issue,Jeanthon efa/. described a rapid fromthe deeptrenches ofthe Pacific 0cean spherical,swimming bacterium that grew fastest in the very methodfor identifying hyperthermophilic methanococci. lt COURTESYKENTAKAI. JAII/STEC hot,high-pressure conditions, The group has now reported exploitsthe Polymerase Chain Reaction (PCR) to amplifya muchmore about its nature, lt turns out also to beable to regionof genesknown to containfeatures uniqueto OPPOSITEPAGETOP: growat muchlower pressures (only 3 timesatmospheric methanogens;then,using enzymes that cut the amplif ied Freeze-fractureelectron micrograph of Methanococcus vulcantus pressure)and temperatures (75'C), although not so well, DNAinto several chunks, the organsims can be identifiedby slratnl,lll , a -this novelhyperthermophilic methanogen Thermococcusbarophilug as they have named it, is a thepattern produced isalso known bythe rather long- isolatedfromthe East Pacific Rise memberof the domain Archaea.lt possesses the fatty acids windedton g ue-twister Restriction Frag ment Len gth COURTESYC,JEANTl]ON, CNRS ROSCOFF uniqueto this group, along with a characteristicapparatus Polymorphism(RFLP). The accuracy of the new method forprotein synthesis, The archaea have some features in wasdetermined bycomparing predicted and actualpatterns OPPOSIIEPAOEBOTTO[/: Spinal commonwith animalcells, along with their bacterial fromknown methanococci,When Jeanthon ef a/.tried this tuberculosisLarge cavitating lyticlesions intwo adjacent lumbar characteristics,These organisms probably resemble the outonmethanogens obtained from as far apartas the Mid- vertebraefroma male aged between 15 earliestlife on this olanet and are considered bv some to AtlanticRidge and the East Pacific Rise,they could identify and25 years atthe time of his death. beaseparate kingdom, somesoecies that had aworldwide distribution, Thesamples were excavated fromthe largegraveyard overlying the site of the Althoughthis species comes from the ocean's depths, Consideringthe large number of microbesthat have been oldRoyal [/int, London The cemetery aJapanesegroup (Takai etal) hasmanaged to isolate foundon the Earth's surface, culturing and identification wasassociated withthe Abbey ofSt It/aryGraces, thelast Cistercian anotherone, which was called Thermaerobacter maycontinue well into the next millennium before these foundaiionin Englandfounded in 1350 marian en s i s,f rom m ud on the world's deepest sea f loor.Th is' inhospitabledeep-sea habitats yield the true diversity of ADGenotyping suggests disease was is1 0897 m belowsea level (yes 1 1 kmdeep!) in the Mariana theirinhabitants. dueto a strain resembling present day TrenchChallenger Deep, off Guamlsland in the Pacific My c ob a cte ri u n tub e rc u I osis r atherthan I V.T. Marteinsson,J.-L.Birrien, A.-L. Reysenbach, M. Vernet, Mycobacteriunbovis. Ocean,One odd aspect of itsgrowth requirements was that D. Marie, A. Gambacorta, P. Messner, IJ.B. Sleytr & D. Prieur. COURTISYi\/ICHAELTAYLOR despitecoming f romsuch a high-pressureenvironment, Thermococcusbarophilus sp. nov., a new barophilic and Thermaerobactermarianenslswould not grow when the hyperthermophilic archaeon isolated under high hydrostatic researchersput it intopressurized containers. This long, thin, pressure from a deep-seahydrothermal vent.lntJ Sy:tBacteriol 49, rod-shapedbacterium required seawater, oxygen and a 35r-359. temoeraturearound 75'C, IC.Jeanthon, S. I-Haridon, A.-L. Reysenbach, E. Come,M. Boththese organisms have fairly conventional nutritional Vernet, P. Messner, IJ.B. Sleyr & D. P tieur. Methanococcus requirements,relying on a mixtureof proteins,sugars and uulcaniussp. nov., anovel hyperthermophilic methanogen isolated from East Pacific Rise, and identification of Methanococcus DSM vitamins, However, marine bacteria can have very d ifferent sp. 427 3T asM eth anococcus sp. nov. I nt Sy st B acta i oI 49, 5 83 -5 89 . needs.There is one distinct group that can use only carbon feruens J dioxideand hydrogen as sources of energy,generating I C. Jeanthon, S. I- Haridon, S. Pradel & D. Prieur. Rapid methanegas as awaste product In the first of two papers in identifi cation of hyperthermophilic methanococci isolated from theissue, Jeanthon ef a/, identif ied two new species of these deep-seahydrothermal vents. lntJ SlstBacteriol 49, r9I-594. so-calledmethanogen s, Methanococcus vulcanius and I K. Thkai, A. Inoue & K. Horikoshi. Therrnaerobactanarianensis Methanococcusfervens,from hydrothermal chimneys in the gen. nov., sp. nov., an aerobic extremely thermophilic marine EastPacif ic Rise and Guayamas Basin, more than 2000 m bacterium from the 1 1000 m deep Mariana Trench . lnt I Sy$Baaeriol beneaththe surface. Again, these organisms prefer 49,619-528. extremesof temperatureand pressures for growth, and this isreflected in their names: vulcaniusrefers to Vulcanus,the Romanfire god, and fervensmeansboiling hot in Latin,

ffi $ffiffi #ffi $#tuffiffiYIoDAYVOL26/MAY99 E knowledgeaboutthis topicand have concluded thatwestillknow surprisinglylittle about the details,Experiments are generallydesig ned to select Microbiology W$p'*"uwws,ii,$xs,'.$ oneparticulartype of advantageousrecombinant, and Strcptomycete sounderestimate the ouantitv of minorand deleterious special issue R,Aaziz& M. Tepfer vanants, Thesechanging populations of RNAviruses are only Tohonourthe career Vrrusesare astrange form of life.They are stripped down resirictedbythe need to maintainviable organisms in the of ProfessorSir David tothe bare essentials of a containerwhichcan recognize a faceof environmentalselection pressures. The authors Hopwood,Microbiology hostcell and then release a setof geneticinstructions to pointout that this continual natural shuff ling may have ispublishing aspecial issue subvertit, This cell,whether inan animal, plant, fungus or ecologicalimplications fora newtype of virus-resistant ofthe journal in autumn bacterium,immediately ignores its normalduties and crop.Plant breeders have achieved this type of cropby 1999in which manyof the commencesreplicating the virus, The new viruses can then constructingtransgenic plants containing aviral gene. The oaoerswill be devoted to the traveltonew unsuspecting host cells leaving their exhausted f irstvi rus-resistant transgenic plants were described in geneticsand molecular ordead benefactor behind, This sort of activitywill usually 1986 butit is particularlytimelyto think abouttheir impact biologyof streptomycetes resultin a disease,and one that can be very diff icultto treat nowbecause three varieties have already been licensed andrelated actinomycetes. becausemost of the virus' activities are actually carried out forcommercialuse in the USA, Thisissue will include a byihenormal constituents of thehealthy host. reviewarlicle by David Forvirusesthat infect plants, one good wayto prevent Theauthors point outthat although we cannotknowthe Hopwood(Fortyyears of diseaseis io usepesticides toeliminate the insects, fungi or f requencyof recombinatron,the very large amount of a gen etic s wtth Strepto myces : nematodesthat spread the virus f romplant to plant.An commercialvirus-resistantcrop suggests that even rare from in vivothrough in vitro alternativeisto breedresistance into commercial crops, recombinationevents are likelyto happen.The plant- toin silico),aswell as peer- althoughthis has often proved impossible, The problem producedviral RNA wrll inevitably be encountered sometime reviewedresearch papers ariseswhen no resistance gene exists, orwhen it proves byan invading virus during its own copying cycle. The fromleading groups, impossibletointroduce itinto the crop, In addition, the authorstherefore go on to explorepossible scenarios with theemphasis on hazards that could arise, Since Forf urtherinformation and virusescan keep ahead of the plant breederthrough recombinationoccurs naturallywhen plants are infected anorderform see ourweb mutatingand recombining into newversions. simultaneously with d ifferent vi ruses, the emphasis must be siteat http://www.socgen Thelarge group called RNAviruses are known to have ondiscovering whetheranycompletely noveltypes of virus microbiol.org.uk manymutantversions, Wheneveran organism copies its canbe produced during infection of avirus-resistant genes,it needsto checkthe accuracy of the new set. The transgenicplant.The most worrying situation might bethe RNAviruseshave nowayof doing this,and indeed gain from appearanceof newviral strains with new propedies theerrors that inevitably creep in. What is more, if two persistinginthe environment, differentRNAviruses happen to beclose togetherwhen theyare copying themselveqthe copy process can get Thereviewers have onlyfound afew experimental reports confused,resulting in a newrecombinantvirus which is a exploringthese possi bilities. For example, tobacco plants mrxtureof both.The f irstrecord of recombinationbetween expressinga gene essential for viral movement throughout RNAviruseswas repoded in 1962 fromaculture of human theplant have been infected with modified viruses in which cellsinfected with two strains of poliovirus.Athird strain with thisgene is i nactivated. Although recombi nant vi ruses mixedfeatures of itstwo parents was isolated from the cells, appeared,none of them produced more severe symptoms Therehave been many more reports since.Although thanthe normal virus. In anoiher series of experiments,new recombinationcan occur between regions of genesthat recombinantviruses were orod uced in the test-tube that arevery similar, italso happens between areas with no gavenovelsymptoms when plants were infected. obvi o u s si m i I arity, Rach id Aazizand M ark Te pfer f rom Unfortunately,there was no comparison with the original lNRA-Versailles, France, have been reviewing current viralstrains, since in real life any new recombinantvirus only persistsif ithas some advantage over other strains.

TheSG M publishestwo monthlyjournals, Afterevaluating the limited published information,the M i cro b io logy anoI o u rn a I of G en e ra I Vi rology. authorsoutline the experiments they think wou ld permit propersafety evaluation of virus-resistant transgenic I lou rnal ofSyste m atic The lnternationa plants,The key ones are com parisons between events in AB0VET publishedquarterly on behalfof the Bacteriologyis non-transgenicplants infected with two viruses and Aschematrc representation of IUMSin conjunction withthe ICSB, recombinationbetween viral RNA and J virus-resistanttransgenic plants infected with each virus transgenemRNA superimposed on Membersmay purchase SGM journals atconcessionary separately.A series of these experiments should show photosofBrasstca napus leaves from for whetherresults arethe same as over previous millions of resistanttransgenic plants (left) and rates.See p, 49 or contactthe MembershipOffice sensitiven0n-transgenic plants(right) details, yearsorwhethersomething quite new happens, bothof which had been infected wlth I Recombination in RNA virusesand in virus-resistant transsenic ttlrnipmosaic potyvrrLls Informationon commercial subscriptions isavailable COURITSYXIARKTEPFER INRA.VERSAITTTS fromthe Journals Sales Office. plants.J G enViro I 80, B 39-I 346.

-* E pSgwr-es.FF4$ si tu{* { ; roDAYVOL26/ MAY99 ffiffiffiffiffi

E,coliaids the YounuLife fightagainst Scieitistof Frurnega sun0urn Year ul( Vacationstudentship Promegasponsors an annualcompetition to encourageyoung life scientists and to promote scientificcommunication skills. Contestants are drawn from five learnedsocieties, including the leadsto published paper SGM. The finalistsare selected by their respective societies on the basisof posteror oral The SGM Vacation presentationsand eachreceives a S200 prize.They then go forwardto competefor the titleof Studentshioscheme has Young Life Scientistof the Year Profilesof the two SG M contestants,Liz Mathew and Susan orovedverv successful in McGrath,appear below g ivingunderg rad uates some The l99Bfinalsof thecompetitiontookplaceattheGeneticalSocietymeetingattheUniversity experienceof workingin a of Warwickon 24 March 1999. The panelof iudgesincluded representatives from allof the researchlaboratory during learnedsocieties participating, The i 0 comp-etitorseach made an oralpresentation abouttheir thesummer holidays before researchand Adele Marstonf romthe Universitvof Oxford,a f inalistf romthe GeneticalSocietv thefinal year of theirBSc. wasthe winnerof a hard-foughtcontest. She receivedS2,OOO and a glasstrophy. ForSarah Smith, an awardee in 1 OQ7 it hac led tn rt rr I rqv rvv !v I am veryinterested wasatthe lrishBranch co-authorshipof a scientific - inlearning about host- meetingat UniversityCollege oaoer a valuableaddition pathogenrnteractions and I Dublinin September 1992 at to her CV.Sarah's supervisor, ameagerto complement whichlwas awardedthe prize Dr RobertJonesof the myexperience in molecular for bestoral communication. University of Portsmouth, virologywitha better As a resultof this I was reportsthat the paper, understandingof the immune nominatedto competefor a entitledA microbiological system,lamcurrently PromegaPrize atthe SGM assayfor the sun protection workingwith S,K.Alex Law meetingat the Universityof factorof sunscreen (MRClmmunochemistry EastAnglia in September productslwas publishedin Unit,Department of 1998 where I was one of the (1 J Pharm Pharmacol 998) Biochemistry,Oxford) on two winners.Ifeelthat it is (supplement), 50 p. 138, leukocyteintegri ns, This extremelyimportantto paper The describesthe positionis temporary and has publicizeresearch and one of developmentof an assay providedme with an ideal the mostimportant mediums using Escherich ia coli Io I LizMathew steppingstone from whichto forthisis through attending measurethe orotection applyfor postdoctoral conferencesand presenting factor commercially of Forme, further education positionsabroad in molecular both in oralandposter availablesunscreen beganat lmperialCollege, rmmunorogy, format.lt isalso an important oroductsas an alternatrve London,My interestin meansof learningabout new e-mailemathew@ molbiol.ox,ac uk tothe current tests which molecularmicrobiology really andupcomino areas of humanvolunteers to use developedafter completing a determinethe effectiveness vacationproject in Deborah I SusanMcGrath ofthe creams against Smith'sgroup on a myoD ultravioletradiation f rom ! homologuein Trichiietla lgraduatedwith a BSc Hons thesun. lndications from the spirallis.I went on to do a inBiomedical Sciences from studyare encouraging and DPhil in Geoffrey Smith's the Universityof Ulsterat a microbiologicalsystem groupat Oxford,which Coleraine(UUC)in1995 maywell providethe basis involved the characterization anditwas during my for an animal-free testinq of a vacciniavirus envelope sandwichplacement year syslem. protein,85R. As with most that my interestin research otherpostgrad uate degrees, began.On completionof my minewas also'character primarydegree, I decidedto building'andmytime in pursuea careerIn researcn Oxfordas a studentwas f un. andbegan my PhDstudies underthe supervision of As padof thetraining Dr R,Haylock and DrJ I receivedduring both under- Dooleyin the Biotechnology researchand vital for forming and postgraduatestudies, Research at collaborations. presentingwork and Group UUC. My PhD studiesinvolved the participatingin Journal Clubs At present,I am studyingthe developmentofan RNA was stronglyencouraged and possible appl ications of assayfor provedto besuitable training Clostridium competitive RT/PC R for the botulinumtoxingene for f inally presenting data detectionof food-borne expressionand during my f rom my own thesis.The 3 pathogensand toxinsat yearsI gainedinvaluable opportunitytotalk at SGM U UC, I hopeto extendmy laboratoryexperience in a conferenceshas provideda knowledgeof molecular widerange of molecular relaxedenvironment within detectionsystems which biologytechn iques. I attended OContributionsfor whichto communicatemy maybe beneficialto the food severalconferences dataand exchangeideas with during industry throug h f uture gradlinefrom younger my PhDwhere I presented otherscientists. Also, winning postdoctorallearn ing and mywork inthe form of poster SGMmembers are the Promegaprize for best ind ustrial experience. andoral commun ications. My openpaper was a nicebonusl welcome, firstcontact with the SGM e-mailmcgrathsusan@hotmail com .. ffiffiffiPubllc

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,*-***91+tT1 ll- Inthis issue, Going A set of two posterson the themeof environmentalmicro- F-' organismshas beenadded to the rangeof SGM educational Publicfocuseson resources. someof SGM's O NaturalWonderscovers the amazingdiversity of microbial ownactivities to habitats,microbial communities and theiressential role in promotethe public keepingthe lifecycles of the planetturnrng. understandingof O Wonderful Workersgives examplesof the applications microbiology, developedby biotechnologistsfor microbesin agriculture, food and pharmaceuticalproduction, pollution control and Contributionsfrom bioremediation. any readerson Mostof the illustrationscame from two SGM-funded proiects asoectof science to producea portfolioof micrographsof micro-organismsat communicationare differentmagnif ications. These were carriedout by summer welcome. studentswho haveproduced an invaluableresource for usein always futureeducational posters and booklets. Singlesets of postersare free from the ExternalRelations Office at SGM Headquarters.Contact Jane Westwellfor The last few daysof February sciences.Whether thrs rs a details(.westwell @socgenm icrobiol.org). saw External Relations reflectionof the education Office staf{ spendingtime systemin Scotlandwe do not in windswept and rainy know,but it was verysatisfy- Glasgow al Careers 2000, ing to see so many young a nationalcareers fair for peoplewho were interested r1f schoolpupils, mature stu- in science, A significant dontc qnd ncnnlp qaekinn nrrmherof oradrratesalso ^h^^^^ Trr d udr EUr ur rar 19E, | ilg sGM came to the stand seeking oroanized Ihe Riosciences adviceon findingwork in A competitionput on by the at il/ork exhibition stand their chosenf ield.This was lnstitutefor Animal Health, in collaborationwith the less encorrraoino.hut the Compton.attracted a good Biochemical Society, the generar^^^^"^l Tneme+A^*^ rnar+h^+ came ranoe of entriesfrom chil- BritishSociety for lmmunol- through was that their drenaged 8-14. Theywere ogy and the BritishPharm- difficulties were probably eclrad ln dacinn a nncter annlnniral Qnriairr drreto noorCV nresentation. illustratingthe importanceof Louis Pasteur'sdiscoveries John Schollar from the Biosciences at Work attends ^^,,^.^t +^i,- ^^^h about micro-organismsand NationalCentre for Biotech- )EVEtAt LdtEEtJ tAil) UALtI drsease. nology Educationput on a year and is the only source 'live' demonstrationwhich of impartialinformation at The entrieswere judged in drew-," '' ororrnsof fascinated these events about higher two aoe flrorns (8-1 1 and Y, onlookers.Once the crowds educationand careersin the 12-14) by staff from the differentdisr^inlines Gl were hooked, volunteers Future Institr,, ,v L, Lv rte Lvt renresentativesoI '-' t"b f romthe societiesmoved in outingswill be [o Manchesler BBSRC (oneof IAH'smalor to'- u'"nive adviceand inform- GN/lEX,3-5 October,and t*{ir q-t , cnnncnrc\ anrf I iz Qnnlzatt " r-*ct ation about the different I nndon'"'/'''t"'*' Olvmnia 13-14 $-t'" the SGM EducationOfficer. biosciencesand choicesin October. The resultswere announced ffi highereducation. in SETweekand the winning tD Jane Westwell, SGM schoolswill receivetheir prizes of S350 for sciencebooks Over29,000 peoplepassed External Relation s Offi ce LizSockett Tracey Reader (BBSRC) and equrpmentat the IAH's Pavilionat the RoyalShow, throrrnhthe dnnrs of the lVlarionBaker (primary school teacher), Stoneleigh,where the top entrieswill also be on display. exhibitionhall over three (lAH DaveCavanagh & Schoo s'Liaison days and a good proportion ElaineCollier (lAH) and Barry 0fficer) wereinterested in biological Freeman(lAH) judging entries inthe Pasteurposter competition

UPPERRIGHT: IheBioscienoe atl4larkexhlbitlon stand aICareers 2000, Glasgow

LOWERRIOHT: The workshops describedopposite were very popular Childrendisplayingtheir microbial with young childrenand we have since taken some o{ art,painted onhandkerchiefs, during IheFanily Science FunDayseuenlal the activitiesto the EdinburghScience Festival. lf there is theUniversity ofReading See p 91 enoughinterest from readerswho are involvedin promoting microbiologyto schools,then we will prepareworksheets for these activities.Please contact Dariel Burdass for details (d,[email protected]).

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The 1999 NationalWeek of Moreambitious, and usually vvrvrScicnr-e rvvl Technnlooy and older, visitors learned the Engineeringwas marked by art of doinga Breed smear the SGM on 20-21 Marchat to calculatethe numberof Ihe Family Science Fun Days, yeastcells in a 5 litrefermen- Universityof Reading.An tation vessel,The prizeof a exhibitioncalled TheSecret bottle of wine or mrcrobial Worldof Microbesillustrated mouse-matoffered incentive the wide diversityof micro- to theseintrepid individuals. organismson earthand the Microscopesbrought previ- impactthat they haveon our ouslyunseen pond life into lives. view and families were Thousandsof visitorscame fascinated by the diversity ro+^ +t^rne FUn E,,^ tr\^.,^uays, rangrng of shape of variousalgae from pre-schoolchildren to and the sight of protozoa grandparenls. The Secret World of Microbes catered for zoomingaround slides in front of theireyes. all age groups with extensiveposter displaysand several Passers-bywere also invitedto have a go at the Lucky types of hands-on activityably supervisedby SGM staff Drp. Winners received a coaster depicting a range of andvolunteers. micro-organisms.Thanks are due to SuperSnapsfor their contributiontowards the cost of the coasters, The SGM activities and posterswere complemented by display material on comoostino from the HenryDoubleday Research Association;posters about sewaoe treatment f rom Thames Water; posters illustrating the water and nitronen r-rrr-lesfrom the BBSRC and NERC and a small display on Ouorn providedby Marlow Foods. Staff from the Environment Pre-and primaryschool aged childrenenjoyed making salt- Agencybrought an exhibition doughmodels or paintingprctures of environmentalmicrobes abouttheir work and a large on cloth handkerchrefs,guided by SGM's new Education dishof pondwater containing grubs and bugsfor childrento Assistant,Dariel Burdass. After a short introductronto several examine.SG M memberNina Jenkins f rom CABI Bioscience, micro-organismswhich affect their every day lives,the SilwoodPark, set up a displayof posters,fungi and locusts childrenwere let looseon the salt-doughand pens.Creative. (deadand alive)to illustratethe LUBILOSAproject which has juicesflowed freely and somebeautiful drawings and models developeda mycoinsecticidefor use agarnstlocusts. John resulted.Handkerchief artists took their picturesaway and Graingerand Bob Rastall,SGM memberswho are staff at 'best' the saltdough modelf rom eachworkshop earned the ReadingUniversity, gave up their weekend to supporl The 'cameraman' winnersome time as on a videomicroscope. Secret World of Microbes and staff from the National Centre Severalchildren left the exhibitionproudly clutching a video for BiotechnologyEducation also contributed enormously. containing30-45 minutesfootage of f reshwaterprotozoa Our gratefulthanks are owed an0argae. to John Schollar,Kate Porter, Othervisitors looked at variousblue cheeses under lenses Bene Watmore and Laura beforespending a messyhalf hour inoculating toilet rolls with Pountney (NCBE); John oystercap mushroomculture. They left with clearinstructions Grainger and Bob Rastall onmushroom care rinoino in their ears! (Un ivers ity of Reading); Kathy Hurst and Gary Holmes;Nina and Jenkins -* Jane Gunn (CABI Bio- science)and staff from the EnvironmentAgency, C Jane Westwell, Dariel Burdass & Janet Hurst work in the SGM External RelationsOffice s-,#**.

IHISPAGE: ScenesatIhe Fanily Science Fun Days eventalIhe University ofReading

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A classified detailscan be easily found. Agood hybridomaproduction, reference accesstomore comprehensive bookforthosewhohave been toa more specialisttextwould textsmay be required, This volume ofi"liffilll3fJ,,,,'brought compendiumof andExercises up'onkits and forthose probablybenecessary ifthe reader ishighly recommended asa basic bookreviews from ByJ. Drtk$ra &C.P. deJager wholiketo understand alittle bit wasinitiating thetechnique inthe referencetextfor all tissue culture 1996 to thepresent PublishedbySpringer-Verlag GmbH moreabout how atechnique works laboratory,Asthe chapters are laboratories, it. organizedunder specif ic lAndySpencer &co. 'l KG 0998) ratherthansimply use isavailable on the DM 48.00/t51081 .00AFrl 35.00/ lBobDalziel applications,ratherthan general Veterinary Laboratory SGM website, S57.00/US$99.00, pp.459 Un ive rsity of Edi nbu rg h techniques,thereis repetition of Agency,Addlestone ISBN:3-540-63759-1 somemethodology, forexample 'Western' blotting.For the reader Thislaboratory manualis aimed lUtolecular Uariabilitywhohas experience ofthese )nartoneltaand Afipia atstudents and teachers ofnlant Vof FungalPathogenstechniquesthisgives an interesting VSpecies Emphasizing virology,and also at research EditedbyP,D, Bridge, Y.Couteaudier insightinto the variety ofways in Bartonella henselae. workersand technicians. lt provides &J, Clarkson whichdifferent laboratories Gontributionsto acomprehensive guideto classical PublishedbyCAB International successfullyreach essentially the Microbiology,Uol. 1 andmodern methods ofhandling (1ss8) sameend-point. Ihave one minor EditedbyA, Schmidt andcharacterizing plantviruses: S55.00/US$100,00,pp,336 quibbleinthat Freund's complete PublishedbyS, KargerAG, Basel theauthors' avowed intention has ISBN:0-85'199-266-8 adjuvant(FCA) isdescribed inone (1es 8) beento stickwith tried and tested chapterascontaining'heat-killed cHFl 46,00/ D M175.00/ US$1 27.00. pp,218 nroceduresandavoid the most Thefungi are mutable beasts, pertussisbacteria' rather than recentdevelopments. Thegreat continuallyexhibiting variability. My c o b a cte ri u m t u b e rc u I o si s. Also ISBN:3-8055-6649-2 majorityof the material inthe book Thiscan be annoying when using thedangers ofFCA for the user if a willbe familiarto theexperienced themas experimentaltools, butis needle*tickinjury occuned should Thisbook isthe first in the plantvirologist:itsmerit is in clearlypart of their nature. This havebeen highlighted, Thisbook Contrib uti o n s toMi uo bi o h gy bringingsuch awide range of bookisan assemblage of19 willbeusefulto both those who series,lt consists of1 4 chaoters methodstogether inone place, In separateaccounts ofvarious alreadyhave some experience in writtenby an international panel, giving sum,89protocols andsub- aspectsoffungal variability, lt is thisarea and, probably in anoverview ofinfection protocols,ranging from infectivity theoutcome ofan EC workshop conjunctionwith other methods causedby Barlonella and Afipia spp. assaytoPCR, are described; there inSeptember'1997, anddoes not texts,to those who wish to embark Thelayout isclear, with tables are17 practical exercises. The attempttogive acomprehensive onnewtechniques. anddiagrams that are easy to descriptionsofthe methods are reviewofthe subject, ltcovers a lsheila Patrick understand,andthe text is well verydetailed and thorough, with widerange offungi, mostly plant, The Q,ueen'sU n iversity written.The sections concerning backgroundinformation onhow invertebrateandhuman pathogens. of Belfast laboratorymethods, including thingswork. Most sections are Theinsect pathogens getmost moleculartechniques, are illustratedwith helpful diagrams. coverage,with six chapters devoted particularlyuseful. The chapters Recommendedasa teaching aid chief ly to M eta rh izi u m and lAnimal GellGulture canbe read independently, aseach andfor laboratories embarking on Beauvaria,one,forexample, VTechniques coversadiscrete subject. However, plantvirus studies, butat the price, describingvariability dueto the EditedbyM,0lynes aminor irritation isthat there is perhapsbeyond the means Resf/esstransposonin Be auvaria- PublishedbySpringer-Verlag GmbH considerablerepetition between ofthe individual student, relatedfungal stains. There isalso a &Co, KG (1998) them.Several comprehensive f Ron Fraser briefaccounl offungal viruses, DM188.00/6S1,373.004Frl70.00/ reviewsolB a fton ella inf ections SGM Marlborough Hous€ whichare unusual bybeing S72,50/US$119.00, pp.618 haveappeared recently inmajor transmittedonlyby intracellular ISBN:3-540-63008-2 journals,including two by some of routes.Inconclusion, thisis a pot- thechapter authors. Given the cost lMolecular pourriof well written accounts, Thisbook provides insight into a ofthis book and the fact that this UBiomethods amongwhich most mycologists widerange ofanimal cell culture fieldis likelyto progress rapidly, I Handbook shouldfind something ofinterest, techniques,particularly those wonderwhowillneed to buy it. lt Editedby R, Rapley &J,M, Walker lGrahamGooday associatedwith biochemistry. wouldbe valuable forinstitution PublishedbyHumana Press (1998) Universityof Aherdeen SectionsonGeneral methods, Cell libraries,andperhaps larger US$89.50,pp.704 proliferationanddeath, Models of departments,butnot for the ISBN: 0-89603-501 -8 celldifferentiation andModels individual,whocan get the same llmmunochemical oftoxicology and pharmacology are informationfrom review journals, Iliked this book and, probably more VProtocols, Second included.Each chapter lays out lNickBrown importantly,sodid my PhD student. Edition.Methods in proceduresgiving precise, step-by- Ad den b roo ke's H ospital, Eachchapter covers 0ne particular MolecularBiology, Uol. 80 stepinstructions which are easy to Cambridge techniquee.g,RFLB HPLC, EditedbyJ.D, Pound readand carry out, The background Southernblots. The chapters vary PublishedbyHumana Press ('1998) informationforeach topic is intheir approach butall give a tJs$69.50 detailed,up-to-date andaccurate, lGenetic Engineering: reasonableoverview ofthe basis of ISBN:0-89603-388-0 Thebook isparticularly suitable for VPrinciplesand thetechniques andsome go into a researcherswhoare relatively new Methods,Uol. 20 littlemore detailand include some Thisbook provides protocols ofa tothe practice ofcell and tissue Editedby J.K. Setlow recipes.lwouldnot recommend it if rangeof immunochemical methods culture,providing asound PublishedbyPlenum Publishing (1998) youwanted to know exactly howto whichare likelyto beof interestto introductiontomany of the modern Corporation pp,292 construct,for example, aYAC, but if molecularbiologists, ltis a treasury applicationsinresearch and US$95,00, youwant to know the rationale ofdetailed information, both within development.However, assuch a ISBN:0-306-4591'l-6 behindthe technique, it'sa good theprotocols andin the Notes widerange oftopics iscovered, the resource.Thechapters are on the sections,which insome chapters depthof information provided is, in Thefirst volume inthis series was published wholewell referenced andso areextensive. However, for someof somecases, limited. Insuch cases in1979, new editions thetechniques covered, such as appearingeach year since then. In

g ffi $*$aqpffi6*tu$}#v ropAY vo L26l MAY99 theearly years the series had an lorun oamage volumeisthe most comprehensive lSpecificity, Function, excellentandstimulating easilyperceived identity, since Vand Repair,Uol. 2: reviewtodate of the methodology Vand Deuelopmentof introductionbyRobin Weiss, which therewere relatively few principles DNARepair in Higher associatedwithsynthetic and NKGells.NKGells: The conveysboth an accurate sense of andmethods todescribe, Genetic Eukaryotes.Gontemporary endogenouslyexpressed ribozymes EffectorArmof Innate historyand real excitement of engineeringisnow used insuch a GancerResearch incellculture andanimal models, lmmuni$. GurrentTopics thingstocome inthe human widevariety of situations, however, EditedbyJ.A, Nickoloff & Detailspertaining toribozyme in Microbiologyand tumourvirus field. Inthe final thatit isinevitable that a series M.F,Hoekstra synthesis,purification and lmmunology,Uol.230 chapter,most of the authors ofthe whichattempts tocoverthe whole PublishedbyHumana Press (1998) biologicalactivity testing are Editedby K. Kiine & M, Colonna otherchapters combine forces to subjectwill lose focus. US$l25,00, pp.672 includedforthe most commonly PublishedbySpringer-Verlag GmbH provideagood overview ofthe Consequently,thisedition includes ISBN:0-89603-500-X studiedribozymes (Hammerhead, &Co. KG (1998) prospectsforvaccination and chaptersspecific tomammalian, Hairpin,Hepatitis Delta Virus and DM224,00/t'S1,636,00/sFr202,00/ therapyofvirally mediated human plantand amoebic systems, Thesecond volume inthis ambitious RNaseP)fora diverse range of S86.00/US$1 49.00, pp, 248 cancer,Asmall reservation isthat togetherwith more generic in vitro paircovers higher eukaryotes, applications,including the targeting ISBN:3-540-63941 -1 byfocusing onhuman tumour andcomputer methods, This whichturn outto be mammals, ofvirusessuch as HlV, hepatitis B virusesbygroup, and not giving diversityisminored bythe range of Plants,the nematode '1.C.elegans, andinfluenza, andcancers ofthe Thisbook isa timely collection of muchdetailon non-human tumour approachestaken by the andfrogs were in Vol, Thearticles breast,pancreas and lung. I excellentarticles on natural killer viruses(e,g. SV40, polyoma) and contributors,Some chapters give aresummaries either of different thoroughlyrecommend this volume (NK) cell activation, receptor humanviruses that cause tumours superficialoverviews, whilst others repairpathways, setsof enzymes, toallnewcomers andestablished interactionanddevelopment. Lysis inanimals (e,9, adenoviruses), some gointo great detail and they range oranalytical methods. Authors are groupsworkingwithribozymes, A oftarget cells and secretion of veryinteresting common evolved inlength from 8 to 48 pages, The acknowledgedexperts inthe field goodcompanion tohave by your cytokinesbyN K cells is controlled mechanismsintumorigenesis are completeseries may provide a andthe result isarticles ofgenerally sideon the lab bench! bydistinct combinations of lostfrom consideration here, usefulresource ina library,but it is veryhigh quality, lSaghirAkhtar inhibitoryand activation receptors. However,thisis a small point unlikelythat this single edition [)verviewsoftranscriptional and Aston University Sincethe latter remain mostly balancedagainstwhat isa highly wouldbe missed from most post-translationalresponsesto elusive,many of the chapters deal recommendedbook, personalbookshelves. genotoxicstress pull together a withthe receptors and co-receptors f EricBlair lGlenn Matthews hugeamount ofdata. There is luirus life in involvedininhibitory function, The UniversityofLeeds Queen Elizabeth overlapbetween afew chapters, VDiagrams roleof NK cells in the lysis of tumour Hospital, Birmingham butin many cases this presentation ByH.-W Ackermann, L,Berthiaume andvirally infected cells is also dealt ofdifferent viewpoints works tothe &M. Tremblay withunder anumber ofheadings, lAdenovirus Methods reade/sadvantage. Thereare PublishedbyCRC Press/Springer- However,NK cells also function Vand Protocols. lCene Regulation. exhaustivereference lists,though VerlagGmbH &Co, KG (1998) bysecreting cytokines, especially Methodsin Molecular VAEukaryotic notevery chapter has clearfigures DM1 45,00/t S1059,004Frl 32,00/ IFN-y,which has an important role Medicine,Uol.2l Perspectiue. Third Edition andtables, Ingeneral there isan $56,00/U5$69.95, pp,221 ininnate defence early in infection EditedbyWS.M.Wdd ByD.S. Latchman excellentandup-to-date (asof ISBN:0-8493-31 26-9 andcan selectively enhance the PublishedbyHumana Press (1998) Published byStanley Thornes early1998) scope ofcoverage that type1 armof the adaptive immune US$99,50,pp.704 (Publishers) Ltd0998) willbe useful toactive researchers Thisis a collection ofpreviously response.From the microbiologist's ISBN:0-89603-551-4 S24,99,pp,329 inD NA repair, students exploring a publisheddiagrams. Asa result pointof view, perhaps one ISBN: 0-7487-3977-7 particulararea, oroutsiders eachdiagram isdrawn ina different weaknessofthe bookwas the Theuse of adenoviruses asgene wantinganoverview ofa subject. styleand for each virus avarying scarcityofinformation onthe deliverysystems guarantees a Thisis an improved edition ofan lRickWood amountofinformation isgiven. functionof N K cells in immunity to stronginterest bymany research alreadyuseful lt basictext, hasbeen ImperialCancer Therehas been noattempt to infectiousdiseases: lessthan a laboratoriesingood protocols for broughtup-to-date andextended, ResearchFund,Clare t standardizetheformat ofeach pageof text is devoted tothe role of constructionofadenovirus mutants thusoffering more to the reader, Hall Laboratories entrysuch that all aspects ofthe life NK cells in anti-bacterial immunity, andrecombinants andtheir use. Partof the revision has been the cycleare covered, There has also lKingston Mills Thisbook caters quite wellforthose inclusionofmore basic materialon beenno apparent attempt toedit National Universityof whosimplywantto grow thegene expression prttcess, thematerialand many diagrams lreland, Maynooth adenoviruses,assaythem and use However,itis particularly pleasing olffitflttit'i,t,,coverthe same processes asthose them,The protocols arewritten ina tosee the additional sections on Riborymes.Methods in onadjacent pages, forexample standard,detailed wayin each post-transcriptionalcontrol,These MolecularMedicine,Uol. 11 thereare seven different diagrams lUirusesand Human chapterandseem easy towork maybe somewhat limited in EditedbyK.J, Scanlon outliningthe pox virus life cycle vGancel from.More advanced topics are coverageincomparison tothe PublishedbyHumana Press (1998) fromentryto maturation. Thisis EditedbyJ,R, Arrand &D,R. Harper included,suchas growth of considerablymoreextensive US$99,50, pp,480 repeatedformany viruses, yetthere PublishedbyBl0S Scientific fastidiousadenoviruses, thestudy treatmentoftranscription, butdo ISBN:0-89603-477-1 is,for example nodiagram outlining PublishersLtd(1998) ofthe immune response to makethis book more balanced, thereplication cycleof the S35,00,pp.200 adenovirusesandmolecular and 0verall,this book is a wellwritten Ribozymesarea class of ribonucleic autonomousparvoviruses, Iam ISBN:1-872748-44-9 cellbiological methods forstudy of andlucid work that provides a acidthat possess enzymatic unsureatwhom this book isaimed: infectionand cell transformation. soundintroduction tothis important propertieswhichcanbe used to lwouldperhaps use it asa teaching Thisis an excellent introduction to ()verall,this is a very comprehensive fieldfor advanced undergraduates, inhibitgene expression ina highly resource;however, ifyou are only humantumour virology, suitable for methodsbook that will be a po$graduatesandresearch sequence-specificmannerby interestedina single virus, Fields advancedundergraduates, laboratorystandard forsome years scientistswhoare not specialists in catalysi ng th e tra n s-cleau ageof isprobably abetter bet, postgraduatesandresearch tocome. thefield, This reasonably priced targetRNA. Assuch these lBobDalziel workersentering thefield. As well f EricBlair paperbackwillbea worthwhile molecules(a.k,a. RNA enzymes) Un ive rsityof Edi nb u rg h astreating each major group of UniversityofLeeds purchaseformany such individuals, havebeen increasingly usedas humantumour viruses in butgiven the rapid pace of advances biologicaltools to understand gene reasonabledetail (hepatitis viruses, inresearch ongene expression, the expression,asdrug-target papillomaviruses,Epstein-Barr authormay be invited to prepare a validationagents and, the focus of viruses,Kaposi's sarcoma, human fourthedition very stlon, thisvolume, aspotential herpesvirusI andoncoretroviruses), llohnMcCarthy therapeuticagents, Thistimely thebook isenhanced byan UMIST,Manchester

ffiffi#ffiffi{sffi*#tuffi#yloDAyvol26/MAy99 E Readers'reactions to the articles on GM crops and food in the February issue of MicrobiologyToday Whatabout the positional effects? DearEditor I greatly appreciatedthe four articleson geneticengineering of In the first issue,Peter Cotgreave rightly beratessloppy plants,for their contentand the courageofthe viewsexpressed. writing about microbes.Nfe must be just ascareful to avoid it However,I wassurprised that no mention wasmade ofposition when venturing into non-microbiologicalcontexts. effects,described abundantly in geneticstextbooks, at least Among the interestingarticles on GM foodsand crops,your thoseofa generationago. The random insertionofa genetic editorial obserues:"Vhat is undoubtedllmotiuating tbe elementinto agenomeby non-homologousrecombination is biotecbnologycompanies at presentis profit and theneation and likely to affectthe information presentand expressedfrom the expansionof marketsbare" . " At present",you write: areyou regionofinsertion, giving riseto unpredictableside-effects expectingchange? Like all businesses,biotechnology separatefrom the functionality ofthe insertedsequence. companiesare always looking for profit. A companyis not a Insertionsmight affectnot only growth pattern and charity; if it neverexpects to beprofitable, therewill be no morphology,but alsometabolic equilibrium which investmentand no company,biotechnological or otherwise. would be lessobvious and more difficult to detect. One of the complaintssometimes levelled at the scientific The textbooksmention examplesofpositional effects community is its unfamiliarity with the realitiesofbusiness and transposableelements from animalsranging from and economics.Surely that cannotinclude the Editor of Drosopbi la tohumans,and BarbaraMcClintock's pioneering MicrobiologyToday. \Wirh studieswith maizearcjustly famous.Later studies with fraternalgreetings. haploid micro-organisms,such as those of\Werner Arber, O Professor Vivian Moses establishedthe importanceof insertionsand inversionsin Division of LifeSciences, King's College London causingspontaneous mutations, especially insertions into plasmidsand bacteriophages. Gonference \With plants,the increasingavailability of sequence information may makeit possibleto targetthe transgeneto G enet icalljt Modified F oods specificregions ofthe genome,by adding host sequencesto & lngredients: tbe uay eachend in an attempt to achieveinsertion by homologous fonuard recombination.But this, and the continuedneed for screening 22-23June 1999 forpositional side-effects,will be time-consumingand counter RoyalMarsden Hospital to industrial pressuresfor commerciallyusable products that NHSTrust, London give profits within a short timescale. ContactIBC Global tO Professor Emeritus Eduard Kellenberger ConferencesLtd IGBM de l'Universite de Lausanne,Switzeiland TeI.01714t31496

Fuilherinformation The featurearticles on GM plants and foodin Mirobiology Todaycoincided with a huge amount ofmedia interest in the topic. Public concernhas been such that many supermarkets and food companieshave now banned GM ingredients from their products.Inquiries into aspectsofthe subjecthave also beenset in motion by the UK governmentand bodiessuch as the Royal Society.As a resultofall this interestseveral useful leafletshave been produced by the researchcouncils.

G M0 s and tlte Enuironment: scientific certaintiesand uncertainties AG page A4briefing note from NERC which examinesthe factsassociated with geneticmodification and assessesthe risks for the natural environment. Available from: NERC Planning & CommunicationsDirectorate, Polaris House, North Star Avenue,Swindon SN 2 IEU (e-mail [email protected]).

. I nG EN E i ous: t b es c i enceand iss ues of genetic ntodifi cat i on A DL size,B pageleaflet from the BBSRC coversthe background to the topic, the debate,issues and concerns,GM and animals, GM and crops,applications and a useful reading list. Available from Public Afiairs Branch,BBSRC, North StarAvenue, Swindon,SN 2 ITJH(e-mail [email protected]). ffiffiw

cl lliilir;I af, i-1 ;-"1"i ilil THEBI0CHEMICALS0CIETYMEETINGftrrelOcHEM[Af s0cmvl\/rn[lc HUMANFUNGALPATH0GENST ;i' iilll",#3'flir j t{L{ :; t';'* .r".."r.:i.,rl i If# Yjilj UniversitvuniversitvofKeeleKeere FUNGALDIM0RPI-|ISI/I ANDDISEASE lj# ffi to-zziliyidbe Granada,spain PROIEINTARGETING: MECHANIS[lIS CYAN0BACTERIA:[/lECHANISMS_0F_..nn,r^nr,rr^'.n,r^^ri"^" n++i". 4-gSepiembel lggg ANDCO[/1PONENTS OFPROTEIN ENERGyC0NVERSI0NANDELECTR0Nt uNrAU|:In€r\/reerngsuilrce SORTINGTOSUBSELLULAR TRANSFER BiochemicalSociety59Porfland Place C0NTACT:J Hendekovn Euro,pean COMPART[/lENTS LondonW1N 3AJ (Iel 0171 580 3481; Gmunden,Austria Faxi:lt1l|JJt%l,0'0171 637 7626; i::'#:'|iil?flX'#,118]fl1[t[iTl,,0bernai,nrStrasboulg, France 5-105-10June1999June 1999 e-maile-mailmeetings@biochemsocorguk;meetings@biochemsoc orguk; Lezay'liarnesia6T080StrasbourgCedex 1-6 0ctober 1999 C6NTACT:C0NTACT:J Hendekovic EuroneanEuropean http://wwwbiochemsoc orguk) France(Fax+33 3 BB 36 69 87; C0NTACT:J.Hendekovic European emaileuresco@esf ScienceFoundation0fficeofEuropean r r. & org: ScienceFoundatron 0fficeofEuropean ResearchConferences (EURSSCO| t quar 5: I i I I i i \. i ji: http:/iwwwesio's/euresco) ResearchConferences (EURESC0) 1quai Lezay-Marnesta670B0StrasbourgCedexq;\'tjq'Ji.|Y*.ffi Lezay-[/arnesia67080Strasbourg Cedex France(Fax+3338836698/:+ST|]HARIfNC0NFFRFNnF France(Fax+33 3BB 36 69 87; UniversityC.ollege c-ork o-mril orrrocnn6oc{ nrn e-maiteuresco@es{ors;FUNCTI3NAL Aspiirs'bii1trne1, v,,,o,,uu'uuuuvuui,u, I, http://wwwesi6rs/euresco) [/lETABILlslllrrrrg'RArNiRriAiiolsHlp 7-eSeptember 1999 http://www e$ org/euresco) ,t : -. * T0BRAIN DEVEL0PMENTAND C0NTACT:The[/eetings0ffice l ,. ., NEUR0DEGENERATIVEDISEASE Biochemicalsociety59Porrrand Prace "r .l i I" ! : ;J i:i1 ; a| ' 0171580 " ;":'": .:, .ti J f' EvnshamHa1. North rrrLeioh.--rrr' !tt{*I]},4J"(Tel 3481: l:j Faxul/l b3/ /b2b: XilI\ITERNAI3NAL \V1R,$mp/ ;i'dffi SECONDFOCUS ONFLUORESCENCE e-maitmeetinss@biochemsocorsuk; syftllpOsltJMRAPIDMETH0DS AND ii_i'iiirinustrgss'- - - SYMPOSIUM:EXCITING DYESAND hrlp://wwwbiochemsoc orsuk) AUT0[/AT|0NSHAPINGTHElNNEW[/ |CR0B|0L00Y [/ILLENNIIJM ":, :-:::--' THEIRAPPLICATIONS 3fliI|IHT#ffiI]T3BIlfrI,.O,',,, YPTFIIIRIB]PIS9I^SITIIA Leiden,The Netherlands KansasState University, USA LondonWlN3AJ (iet 0171 580 3481: 26-27November 1999 e-16Julyleee [[!'jBiflt|^K^i,YA,n5l'"u Fax0i71637 7626; iiia'iliA'$illtinruftFbnr' C0NTACT:[/slrme van der Heijden, C0NTACT:JaniceNikkelConference email,meetingsPbiochemsoc orguk' I [/olecularProbes Europe Poortgebouw Coordinator(Tel +178bb32254i]: http://wwwbiochemsocorguk)Castelvecchio.Pasc_oli,ltaly Rijnsburgerweg10,2333 AALeiden e-maile-mailjnikkel@dce,ksu,edu;http:llwww,jnikkel@dce,ksu,edu:http://www 11-16September1999II-IUuEPrEIIruErruui' TheNetherlands (Tel+31 71 523 3378; F,..d{ *",ij^,s".t ._*** ,Ib.L*,&, s., ." t'li a\,$q dceksueduidce/conf/microbiolosy/) O0NTACTJHendekovic European Fax+31715233419; - 5Il l:-.^ i li' ,r il;f "+'; NMR-lNM0IECUtARBIOLO6I.".^:f. ._;._.^^^:" " SctenceFoundation0fficeofEuropean e-maileurotech@probes nl) sTRlcTlRFRtNntNnANn MICR0BIALAQUATICSYMBI0SIS.ResearchConferences(EURESC0),1 quar tl i",- "',,'I : " x710tigi1iA.pRiabcftiigN PRESENTEDBYTHE J0INT AQUATIC Lezay-l/arnesia,67080 StrasbcursCedex " j ." "."\ ASS0CIATIONS0FTHEUK France(Fax+33 3BB 36 69 87: ."";;.:;'.1; e-maiieuresco@esfors: fdlffiSliils'JL AssociationforMarine ADVAI\ICEDCOURSE ON[/ICROBIAL lq{,t! " PHYSIOLOGYAND FER[/ ENTATION ''NTACT:JHendekovcEuroleanfl'$tri'11iil;;;; ffi IECHNO LOGY scienceFoundation0fficeofEurcpean pHySI0L0Gy0FF00DRELATED nnn,rnnr,n,n^,,^r^"r\r^r^.,i^c^^+i"h DelftUniversity olTechnology, ResearchConferences (EURESC0) 1quai jll^ll^YiiY,1'^'l:l'll'l'"i::"''"MICR0 0RGANISMS THE17TH nrrur;rdtrurii"l | ''' 'to' 'l'l TheNetherlands Lezay-Marnesia67080Strasb ou"' n'd'" SYx4P0 I 17lF IH E INTE (Iel01631 bb/832;.o:ftl luj ::oll,faxulbsl "", SU 0 RNATI0NAL 6-17December 1999 France(Fax+83 3 BB 36 69 87; f4344tD inn,rrurnrr0NF00D MtcR0Bl0L0Gy 571150:e-maildmck@dmlacuk; e-maileuresco@esforg: '"""lfrfii IYGIENE (lCF[/H) C0NTACT:Drlr L A vander Meer-Lerk http://wwwesfrrg/euiesco), http://wwwnerc-obanacuk/dmll In$ituteforBiotechnology StudiesDelft - Leiden(B0DL) Kluyver Laboratory ENzyr\,rrr',TfrEENVRTNT\,,ilr YfIitl'J{JXfr},1.$3['"0'Julianalaan672628 BC Delft The ACTIVITYEC0L0GYAND ""ryHHHHHnr-irurnnfiruil\rtrur\rrtrt|\rtrt, AppLtCntnruS ANNEXINS C0NTACT,ICFMHCongress Servrce Netherlands(Tel+31 15 2181922', BrabantTheNethedands (Fax+31 40 Fax+31 15 2182355,e-mallbodl@$m Granada,Spain WyeCollege., rryl^^ tudelftnl; http://www kluyver $m tudelft 12-lEJuryleee i-'rs'pt'i'r6iijiigg ifll9?f,*fli31fff9,1,Ti3';1;j'nl/B0DL/ACShtm) c0NTACT:The[/eetingsOffice r! c0NTACT:secrerariatDrJose-[/inrrcr ^ DIFrGUTFUNCTI0NANDHEALTH '"*.i:"\ BareaConsejoSuperiorde'suu'Biochemtcalsociety5gPortlandPlace :l' i' ,i!* LondonW'lN3AJ (Tel 0171 580 3481; TheRoyal Society ol Medicine ; *. tnvpsrinrninnpstipnrifinrs-"'*'ar'r,,,0,.t,Fsrrninn ,t:; ""i ".'L'"r Experimentaldellaidin Profesor Fax0171 637 7626: london gEYONITUTGENOIT 1 lgnngfirrnrr]r Snain rror *:+ in ii" e-mailmeetings@biochemsoc orguk, z?-zlSeptember 1999 1BTH INTERNATIONAL CONGRESS http://wwwbiochemsoc orsuk) i0iii;* .34ttill gooo, 00NTACT:EmmaBrvce The Rovat socretv OFBIOCHEMISTRY ANDMOLECULAR [email protected],es:fUtrtlnttrtf HttnLnSPECIS 0FSURFACE oIMedrcrne 1WrmnoleStreet London BIOLOGY edu/grenada/) j http://wwwcssorst sclINCE:STRUCTU REAN D DYNAMICS wlM BAE 0et 017 290 3919; InternationalConference F,t I/JRIND0R FSE^SSCITy F3R' p.lqBlAN]QAIIDBI0L0GICAL Fax01112e029,77', Centre,Birmingham npFLifnMtlnOetOLOefSU[/MlR" [/I0LECULES ATINIERFACES e-mail:events@roysocmedacuk) 16-20 July 2000 C0NFERENCE CastelvecchioPascoli, ltaly C0NTACT;AndreaBuxton Centre UniversityofYork 3-8September 1999 ExhibitionsTheNEC Birmingham 840 14-16Ju|y1999 C3NTACT:J.HendekovicEuropean 1NT(Tel 0121 76/ 3755; Fax0121 16l genome@necgroup C0 NTACT: DrAn n Bai llie, Society for ScienceFoundati on,0ffrce _ofEuropean 3535;e-mail couk) Applied[/icrobiology iheBloreiowe, ResearchCorferencel{lURESC0) 1quai ly3tnesnr6T-0pQCedex, TheHarpur Centre 1jedford MKag 1iq fezav itlqsbrurg (Tel01 i34 326661; Fax01 234 326678; France (Fax+33 3 BB 36 69 87; emailsfam@btinternetcom) e-maileuresco@esf org; htto://www.esf. orq/euresco)

ffi ##ffi#ffi $#*-#ffiyToDAyvoL26/MAy99 IIU l J Gomment

Yourviewsonthenew MicrobiologyTday

It tookMicrobiology lcong.atulations on a smart and highly professional )AlcrobiologyToday J Todayhomeoverthe V new publication. The first issueof MicrobiologyToday V looks extremelvsmart weekend to read.I thought suggeststhat it hastransformed from a good publication in its new designbut I am it was really stupendous. of the memb ers(The Quarterly) to a magazine that can be afraidthat for my ageing You and your team have passedto non-members for information and opinion on eyesimproved style hasbeen certainly made a really matters of importance. The timing of the articles on GM achievedat the sacrificeof excellentiob ofit. cropswas fortuitous and you should run on somespare readability - main stories I The' Quarterly' has been copiesof thosearticles for distribution to our opinion- can just about copewith but transformed into a really formers. My view of the new format and title is, ofcourse, MicroShorts, Meetings and professional,high-class entirely unbiasedby the fact that it contains an article by Reviews areall something of magazine for the Society. one ofour 1998 finalists and the announcement of a Prize a challenge. The articles are really very Lectureship to one ofour staff! ProfessorRoy R. Russell,, good and comment on ProfessorNigel L. Brown, Schoolof BiologicalSciences, The Dental School, Un iversity really important issues.The Un iversity of Bi rm ing ham of N ew castle -u po n -Tyn e whole layout is alsovery

[l.i)i. ! tIl r! rf d.oinn.i.i I professionallooking, the lAbri.fnotero Todayis an exrremely disappointing jD )ulcrobiology ihir 't I | !611i)1 rifril, red bullets areremarkably V congratulate you and V replacement for the .lGM Ouarterly. The font effective.Please feel free your colleagues on the first throughout is too small und in cJtain se.tions hasmade the to passthese hearty issue of Microbiology Today - text unreadable.Did anyoneopen Reviews and compare it congratulations on to others I started at page 1 and read with the Book Reviews in the last Quararly? I cannot in your team. \Well done. solidly through to the end - believe they would still havemailed it if they had. The Professor John C. Fry, it was absorbing, bullet points arean irritating mess.Please do not compress Cardiff Schoolof interesting and educational. the text somuch in future issuesthen we might seethe Biosciences Dr M.O. Moss, Surrey content. Mrs D. Wyatt, RegionalVirus Laboratory, 1|The contentsofthe Februaryissue are inreresting, The Queen's Universityof Belfast V useful and enjoyable.Howeveq the type gives me problems both for sizeand legibility. In particular the )tW;croTodaylooks lcnraru... compressed,thin sansseriftype usedin legends,news items Vexcellent-welldone Vwelldone. and the meetings section is a real problem - and others agree on agreat job. Professor NickRusse{ with me. Furthermore, you havereduced the sizeof type for RegEngland, Convener, M i cro b io Iogy Laborato ri es, the articles to apoint that is barely tolerable and a bit tiring Fermentation & Wye College University of for people like me. I am appreciativeof the evident intention Bioprocessing Group London to make MicrobiologyToday anecessaryand useful read for the members, but pleasedo not make it too difficult. MT launch Professor Robert G.E. Murray, Microbiology and lmmunology, University of Western Ontario, Canada lA l,rnch was held to mark the launch ofthe new J magazine.The production and distriburion ream ar Madborough House was joined by the Editor Dave Roberts, lfhepages aremuch morevisually striking than Vpreviously and the whole magazinehasa freshand the designer,Ruth Gregory, from Graphics International trendier look about it. You must be very pleasedwith it. The who was responsiblefor the new look, Ina Cocks from \STarwick changing font stylesmake the text look busy and the N\7H Sales,and Paul Yates andJohn Young from job squashedupright format is difficult to read. . . Printers who made such an excellent of turning the H oward J en ki n so n, C onve n er, design into print. \(/e were sorry that the editorial board Cells &Cell Surtaces Group members were unable to ioin the celebrations. The editorial team hastaken note of comments on the style and sizeof rypeface.These will be changedin due course to improve the readabil ity of MicrobiolagyTod.ay. Pleaselet us know your views. llu ffi $#ffi#ffi$*tu#ffiyroDAyvol26/MAy99